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                                                            Customer No. 1208

                          MASTER LOAN AND SECURITY AGREEMENT


          THIS AGREEMENT dated as of December 23, 1998, is made by Trega
Biosciences, Inc. (the "Borrower"), a Delaware corporation having its principal
place of business and chief executive office at 9880 Campus Point Drive, San
Diego, California, 92121 in favor of Transamerica Business Credit Corporation, a
Delaware corporation (the "Lender"), having its principal office at Riverway II,
West Office Tower, 9399 West Higgins Road, Rosemont, Illinois 60018.

     WHEREAS, the Borrower has requested that the Lender make Loans to it from
time to time; and

     WHEREAS, the Lender has agreed to make such Loans on the terms and
conditions of this Agreement.

     NOW, THEREFORE, in consideration of the premises and to induce the Lender
to extend credit, the Borrower hereby agrees with the Lender as follows:

     SECTION 1.     DEFINITIONS.  

     As used herein, the following terms shall have the following meanings, and
shall be equally applicable to both the singular and plural forms of the terms
defined:

AGREEMENT shall mean this Master Loan and Security Agreement together with all
schedules and exhibits hereto, as amended, supplemented, or otherwise modified
from time to time.  

APPLICABLE LAW shall mean the laws of the State of Illinois (or any other
jurisdiction whose laws are mandatorily applicable notwithstanding the parties'
choice of Illinois law) or the laws of the United States of America, whichever
laws allow the greater interest, as such laws now exist or may be changed or
amended or come into effect in the future.

BUSINESS DAY shall mean any day other than a Saturday, Sunday, or public holiday
or the equivalent for banks in New York City.

CODE shall have the meaning specified in Section 8(d).

COLLATERAL shall have the meaning specified in Section 2.

COLLATERAL ACCESS AGREEMENT shall mean any landlord waiver, mortgagee waiver,
bailee letter, or similar acknowledgement of any warehouseman or processor in
possession of any Equipment.

EFFECTIVE DATE shall mean the date on which all of the conditions specified in
Section 3.3 shall have been satisfied.

EQUIPMENT shall have the meaning specified in Section 2.

EVENT OF DEFAULT shall mean any event specified in Section 7.

FINANCIAL STATEMENTS shall have the meaning specified in Section 6.1.

GAAP shall mean generally accepted accounting principles in the United States of
America, as in effect from time to time.

LOANS shall mean the loans and financial accommodations made by the Lender to
the Borrower in accordance with 

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the terms of this Agreement and the Notes.


LOAN DOCUMENTS shall mean, collectively, this Agreement, the Notes, and all
other documents, agreements, certificates, instruments, and opinions executed
and delivered in connection herewith and therewith, as the same may be modified,
extended, restated, or supplemented from time to time.

MATERIAL ADVERSE CHANGE shall mean, with respect to any Person, a material
adverse change in the business, prospects, operations, results of operations,
assets, liabilities, or condition (financial or otherwise) of such Person taken
as a whole and in light of the nature of such person's business.

MATERIAL ADVERSE EFFECT shall mean, with respect to any Person, a material
adverse effect on the business, prospects, operations, results of operations,
assets, liabilities, or condition (financial or otherwise) of such Person taken
as a whole and in light of the nature of such person's business.

NOTE shall mean each Promissory Note made by the Borrower in favor of the
Lender, as amended, supplemented, or otherwise modified from time to time.

OBLIGATIONS shall mean all indebtedness, obligations, and liabilities of the
Borrower under the Notes and under this Agreement, whether on account of
principal, interest, indemnities, fees (including, without limitation,
attorneys' fees, remarketing fees, origination fees, collection fees, and all
other professionals' fees), costs, expenses, taxes, or otherwise.

PERMITTED LIENS shall mean such of the following as to which no enforcement,
collection, execution, levy, or foreclosure proceeding shall have been
commenced:  (a) liens for taxes, assessments, and other governmental charges or
levies or the claims or demands of landlords, carriers, warehousemen, mechanics,
laborers, materialmen, and other like Persons arising by operation of law in the
ordinary course of business for sums which are not yet due and payable, or liens
which are being contested in good faith by appropriate proceedings diligently
conducted and with respect to which adequate reserves are maintained to the
extent required by GAAP; (b) deposits or pledges to secure the payment of
worker's compensation, unemployment insurance, or other social security benefits
or obligations, public or statutory obligations, surety or appeal bonds, bid or
performance bonds, or other obligations of a like nature incurred in the
ordinary course of business; (c) licenses, restrictions, or covenants for or on
the use of the Equipment which do not materially impair either the use of the
Equipment in the operation of the business of the Borrower or the value of the
Equipment; and (d) attachment or judgment liens that do not constitute an Event
of Default.

PERSON shall mean any individual, sole proprietorship, partnership, limited
liability partnership, joint venture, trust, unincorporated organization,
association, corporation, limited liability company, institution, entity, party,
or government (including any division, agency, or department thereof), and the
successors, heirs, and assigns of each.

SCHEDULE shall mean each Schedule in the form of Schedule A hereto delivered by
the Borrower to the Lender from time to time.

SOLVENT means, with respect to any Person, that as of the date as to which such
Person's solvency is measured:

     (a)  the fair saleable value of its assets is in excess of the total amount
of its liabilities (including contingent liabilities as valued in accordance
with GAAP) as they become absolute and matured;

     (b)  it has sufficient capital to conduct its business; and 

     (c)  it is able generally to meet its debts as they mature.  

TAXES shall have the meaning specified in Section 5.5.

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     SECTION 2.     CREATION OF SECURITY INTEREST; COLLATERAL.  The Borrower 
hereby assigns and grants to the Lender a continuing general, first priority 
lien on, and security interest in, all the Borrower's right, title, and 
interest in and to the collateral described in the next sentence (the 
"Collateral") to secure the payment and performance of all the Obligations.  
The Collateral consists of all equipment set forth on all the Schedules 
delivered from time to time under the terms of this Agreement (the 
"Equipment"), together with all present and future additions, parts, 
accessories, attachments, substitutions, repairs, improvements, and 
replacements thereof or thereto, and any and all proceeds thereof, including, 
without limitation, proceeds of insurance and all manuals, blueprints, 
know-how, warranties, and records in connection therewith, all rights against 
suppliers, warrantors, manufacturers, sellers, or others in connection 
therewith, and together with all substitutes for any of the foregoing.

     SECTION 3.     THE CREDIT FACILITY.  

          Section 3.1.   BORROWINGS.  Each Loan shall be in an amount not 
less than $100,000, and in no event shall the sum of the aggregate Loans made 
exceed the amount of the Lender's written commitment to the Borrower in 
effect from time to time.  Notwithstanding anything herein to the contrary, 
the Lender shall be obligated to make the initial Loan and each other Loan 
only after the Lender, in its sole discretion, determines that the applicable 
conditions for borrowing contained in Sections 3.3 and 3.4 are satisfied.  
The timing and financial scope of Lender's obligation to make Loans hereunder 
are limited as set forth in a commitment letter executed by Lender and 
Borrower, dated as of November 25, 1998 and attached hereto as Exhibit A (the 
"Commitment Letter").

          SECTION 3.2.   APPLICATION OF PROCEEDS.  The Borrower shall not
directly or indirectly use any proceeds of the Loans, or cause, assist, suffer,
or permit the use of any proceeds of the Loans, for any purpose other than for
the purchase, acquisition, installation, or upgrading of Equipment or the
reimbursement of the Borrower for its purchase, acquisition, installation, or
upgrading of Equipment.

          SECTION 3.3.   CONDITIONS TO INITIAL LOAN.  

     (a)  The obligation of the Lender to make the initial Loan is subject to
the Lender's receipt of the following, each dated the date of the initial Loan
or as of an earlier date acceptable to the Lender, in form and substance
satisfactory to the Lender and its counsel:

          (i)   completed requests for information (Form UCC-11) listing all
     effective Uniform Commercial Code financing statements naming the Borrower
     as debtor and all tax lien, judgment, and litigation searches for the
     Borrower as the Lender shall deem necessary or desirable;

          (ii)  Uniform Commercial Code financing statements (Form UCC-1) duly
     executed by the Borrower (naming the Lender as secured party and the
     Borrower as debtor and in form acceptable for filing in all jurisdictions
     that the Lender deems necessary or desirable to perfect the security
     interests granted to it hereunder) and, if applicable, termination
     statements or other releases duly filed in all jurisdictions that the
     Lender deems necessary or desirable to perfect and protect the priority of
     the security interests granted to it hereunder in the Equipment related to
     such initial Loan;

          (iii) a Note duly executed by the Borrower evidencing the amount of
     such Loan; 

          (iv)  a Collateral Access Agreement duly executed by the lessor or
     mortgagee, as the case may be, of each premises where the Equipment is
     located;

          (v)   certificates of insurance required under Section 5.4 of this
     Agreement together with loss payee endorsements for all such policies
     naming the Lender as lender loss payee and as an additional insured;

          (vi)  a copy of the resolutions of the Board of Directors of the
     Borrower (or a unanimous consent of directors in lieu thereof) authorizing
     the execution, delivery, and 

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     performance of this Agreement, the other Loan Documents, and the 
     transactions contemplated hereby and thereby, attached to which 
     is a certificate of the Secretary or an Assistant Secretary of the
     Borrower certifying (A) that the copy of the resolutions is true, complete,
     and accurate, that such resolutions have not been amended or modified since
     the date of such certification and are in full force and effect and (B) the
     incumbency, names, and true signatures of the officers of the Borrower
     authorized to sign the Loan Documents to which it is a party; and
          
          (vii) such other agreements and instruments as the Lender deems
     necessary in its sole and absolute discretion in connection with the
     transactions contemplated hereby.

     (b)  There shall be no pending or, to the knowledge of the Borrower after
due inquiry, threatened litigation, proceeding, inquiry, or other action
(i) seeking an injunction or other restraining order, damages, or other relief
with respect to the transactions contemplated by this Agreement or the other
Loan Documents or thereby or (ii) which affects or could affect the business,
prospects, operations, assets, liabilities, or condition (financial or
otherwise) of the Borrower, except, in the case of clause (ii), where such
litigation, proceeding, inquiry, or other action could not be expected to have a
Material Adverse Effect in the judgment of the Lender.

     (c)  The Borrower shall have paid all fees and expenses required to be paid
by it to the Lender as of such date. 

     (d)  The security interests in the Equipment related to the initial Loan
granted in favor of the Lender under this Agreement shall have been duly
perfected and shall constitute first priority liens.

          SECTION 3.4.   CONDITIONS PRECEDENT TO EACH LOAN.  The obligation of
the Lender to make each Loan is subject to the satisfaction of the following
conditions precedent:

     (a)  the Lender shall have received the documents, agreements, and
instruments set forth in Section 3.3(a)(i) through (v) applicable to such Loan,
each in form and substance satisfactory to the Lender and its counsel and each
dated the date of such Loan or as of an earlier date acceptable to the Lender; 

     (b)  the Lender shall have received a Schedule of the Equipment related to
such Loan, in form and substance satisfactory to the Lender and its counsel, and
the security interests in such Equipment related to such Loan granted in favor
of the Lender under this Agreement shall have been duly perfected and shall
constitute first priority liens;

     (c)  all representations and warranties contained in this Agreement and the
other Loan Documents shall be true and correct on and as of the date of such
Loan as if then made, other than representations and warranties that expressly
relate solely to an earlier date, in which case they shall have been true and
correct as of such earlier date; 

     (d)  no Event of Default or event which with the giving of notice or the
passage of time, or both, would constitute an Event of Default shall have
occurred and be continuing or would result from the making of the requested Loan
as of the date of such request; and

     (e)  the Borrower shall be deemed to have hereby reaffirmed and ratified
all security interests, liens, and other encumbrances heretofore granted by the
Borrower to the Lender.

     SECTION 4. THE BORROWER'S REPRESENTATIONS AND WARRANTIES.  

          SECTION 4.1.   GOOD STANDING; QUALIFIED TO DO BUSINESS.  The Borrower
(a) is duly organized, validly existing, and in good standing under the laws of
the State of its organization, (b) has the power and authority to own its
properties and assets and to transact the businesses in which it is presently,
or proposes to be, engaged, and (c) is duly qualified and authorized to do
business and is in good standing in every 

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jurisdiction in which the failure to be so qualified could have a Material 
Adverse Effect on (i) the Borrower, (ii) the Borrower's ability to perform 
its obligations under the Loan Documents, or (iii) the rights of the Lender 
hereunder.

          SECTION 4.2.   DUE EXECUTION, ETC.  The execution, delivery, and
performance by the Borrower of each of the Loan Documents to which it is a party
are within the powers of the Borrower, do not contravene the organizational
documents, if any, of the Borrower, and to the best knowledge of the Borrower,
do not (a) violate any law or regulation, or any order or decree of any court or
governmental authority, (b) conflict with or result in a breach of, or
constitute a default under, any material indenture, mortgage, or deed of trust
or any material lease, agreement, or other instrument binding on the Borrower or
any of its properties, or (c) require the consent, authorization by, or approval
of or notice to or filing or registration with any governmental authority or
other Person.  This Agreement is, and each of the other Loan Documents to which
the Borrower is or will be a party, when delivered hereunder or thereunder, will
be, the legal, valid, and binding obligation of the Borrower enforceable against
the Borrower in accordance with its terms, except as enforceability may be
limited by bankruptcy, insolvency, or similar laws affecting creditors' rights
generally and by general principles of equity.

          SECTION 4.3.   SOLVENCY; NO LIENS.  The Borrower is Solvent and will
be Solvent upon the completion of all transactions contemplated to occur
hereunder (including, without limitation, the Loan to be made on the Effective
Date); the security interests granted herein constitute and shall at all times
constitute the first and only liens on the Collateral other than Permitted
Liens; and the Borrower is, or will be at the time additional Collateral is
acquired by it, the absolute owner of the Collateral with full right to pledge,
sell, consign, transfer, and create a security interest therein, free and clear
of any and all claims or liens in favor of any other Person other than Permitted
Liens.

          SECTION 4.4.   NO JUDGMENTS, LITIGATION.  No judgments are outstanding
against the Borrower nor is there now pending or, to the best of the Borrower's
knowledge after diligent inquiry, threatened any litigation, contested claim, or
governmental proceeding by or against the Borrower except judgments and pending
or threatened litigation, contested claims, and governmental proceedings which
would not, in the aggregate, have a Material Adverse Effect on the Borrower.

          SECTION 4.5.   NO DEFAULTS.  The Borrower is not in default or has not
received a notice of default under any material contract, lease, or commitment
to which it is a party or by which it is bound.  The Borrower knows of no
dispute regarding any contract, lease, or commitment which could have a Material
Adverse Effect on the Borrower.

          SECTION 4.6.   COLLATERAL LOCATIONS.  On the date hereof, each item of
the Collateral is located at the place of business specified in the applicable
Schedule.

          SECTION 4.7.   NO EVENTS OF DEFAULT.  No Event of Default has occurred
and is continuing nor has any event occurred which, with the giving of notice or
the passage of time, or both, would constitute an Event of Default.

          SECTION 4.8.   NO LIMITATION ON LENDER'S RIGHTS.  Except as permitted
herein, none of the Collateral is subject to contractual obligations that may
restrict or inhibit the Lender's rights or abilities to sell or dispose of the
Collateral or any part thereof after the occurrence of an Event of Default.

          SECTION 4.9.   PERFECTION AND PRIORITY OF SECURITY INTEREST.  This
Agreement creates a valid and, upon completion of all required filings of
financing statements, perfected first priority and exclusive security interest
in the Collateral, securing the payment of all the Obligations.

          SECTION 4.10.  MODEL AND SERIAL NUMBERS.  The Schedules set forth the
true and correct model number and serial number of each item of Equipment that
constitutes Collateral.

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          SECTION 4.11.  ACCURACY AND COMPLETENESS OF INFORMATION.  All data,
reports, and information heretofore, contemporaneously, or hereafter furnished
by or on behalf of the Borrower in writing to the Lender or for purposes of or
in connection with this Agreement or any other Loan Document, or any transaction
contemplated hereby or thereby, are or will be true and accurate in all material
respects on the date as of which such data, reports, and information are dated
or certified and not incomplete by omitting to state any material fact necessary
to make such data, reports, and information not misleading at such time.  There
are no facts now known to the Borrower which individually or in the aggregate
would reasonably be expected to have a Material Adverse Effect and which have
not been specified herein, in the Financial Statements, or in any certificate,
opinion, or other written statement previously furnished by the Borrower to the
Lender.

          SECTION 4.12.  PRICE OF EQUIPMENT.  The cost of each item of Equipment
does not exceed the fair and usual price for such type of equipment purchased in
like quantity and reflects all discounts, rebates and allowances for the
Equipment (including, without limitation, discounts for advertising, prompt
payment, testing, or other services) given to the Borrower by the manufacturer,
supplier, or any other person.

     SECTION  5.    COVENANTS OF THE BORROWER.  

          SECTION 5.1.   EXISTENCE, ETC.  The Borrower shall:  (a) retain its
existence and its current yearly accounting cycle, (b) maintain in full force
and effect all licenses, bonds, franchises, leases, trademarks, patents,
contracts, and other rights necessary or desirable in its judgment to the proper
conduct of its business unless the failure to do so could not reasonably be
expected to have a Material Adverse Effect on the Borrower, (c) continue in, and
limit its operations to, the same general lines of business as those presently
conducted by it, and (d) comply with all applicable laws and regulations of any
federal, state, or local governmental authority, except for such laws and
regulations the violations of which would not, in the aggregate, have a Material
Adverse Effect on the Borrower.

          SECTION 5.2.   NOTICE TO THE LENDER.  As soon as possible, and in any
event within ten days after the Borrower learns of the following, the Borrower
will give written notice to the Lender of (a) any proceeding instituted or
threatened to be instituted by or against the Borrower in any federal, state,
local, or foreign court or before any commission or other regulatory body
(federal, state, local, or foreign) involving a sum, together with the sum
involved in all other similar proceedings, in excess of $100,000 in the
aggregate, (b) any contract that is terminated or amended and which has had or
could reasonably be expected to have a Material Adverse Effect on the Borrower,
(c) the occurrence of any Material Adverse Change with respect to the Borrower,
and (d) the occurrence of any Event of Default or event or condition which, with
notice or lapse of time or both, would constitute an Event of Default, together
with a statement of the action which the Borrower has taken or proposes to take
with respect thereto.

          SECTION  5.3.  MAINTENANCE OF BOOKS AND RECORDS.  The Borrower will 
maintain books and records pertaining to the Collateral in such detail, form, 
and scope as the Lender shall require in its commercially reasonable 
judgment. The Borrower agrees that the Lender or its agents may enter upon 
the Borrower's premises at any time and from time to time during normal 
business hours, and at any time upon the occurrence and continuance of an 
Event of Default, for the purpose of inspecting the Collateral and any and 
all records pertaining thereto. Notwithstanding the foregoing to the 
contrary, Lender shall comply with all life, health and safety policies and 
procedures of Borrower while on Borrower's premises.  No inspection shall 
disrupt Borrower's operations.

          SECTION 5.4.   INSURANCE.  The Borrower will maintain insurance on the
Collateral under such policies of insurance, with such insurance companies, in
such amounts, and covering such risks as are at all times reasonably
satisfactory to the Lender.  All such policies shall be made payable to the
Lender, in case of loss, under a standard non-contributory "lender" or "secured
party" clause and are to contain such other provisions as the Lender may
reasonably require to protect the Lender's interests in the Collateral and to
any payments to be made under such policies.  Certificates of insurance policies
are to be delivered to the Lender, premium prepaid, with the loss payable
endorsement in the Lender's favor, and shall provide for not less than thirty
days' prior written notice to the Lender, of any alteration or cancellation of
coverage.  If the Borrower fails to maintain such insurance, the 

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Lender may arrange for (at the Borrower's expense and without any 
responsibility on the Lender's part for) obtaining the insurance.  Unless the 
Lender shall otherwise agree with the Borrower in writing, the Lender shall 
have the sole right, in the name of the Lender or the Borrower, to file 
claims under any insurance policies, to receive and give acquittance for any 
payments that may be payable thereunder, and to execute any endorsements, 
receipts, releases, assignments, reassignments, or other documents that may 
be necessary to effect the collection, compromise, or settlement of any 
claims under any such insurance policies. 

          SECTION 5.5.   TAXES.  The Borrower will pay, when due, all taxes,
assessments, claims, and other charges ("Taxes") lawfully levied or assessed
against the Borrower or the Collateral other than taxes that are being
diligently contested in good faith by the Borrower by appropriate proceedings
promptly instituted and for which an adequate reserve is being maintained by the
Borrower in accordance with GAAP.  If any Taxes remain unpaid after the date
fixed for the payment thereof, or if any lien shall be claimed therefor, then,
without notice to the Borrower, but on the Borrower's behalf, the Lender may pay
such Taxes, and the amount thereof shall be included in the Obligations.

          SECTION 5.6.   BORROWER TO DEFEND COLLATERAL AGAINST CLAIMS; FEES ON
COLLATERAL.  The Borrower will defend the Collateral against all claims and
demands of all Persons at any time claiming the same or any interest therein. 
The Borrower will not permit any notice creating or otherwise relating to liens
on the Collateral or any portion thereof to exist or be on file in any public
office other than Permitted Liens.  The Borrower shall promptly pay, when
payable, all transportation, storage, and warehousing charges and license fees,
registration fees, assessments, charges, permit fees, and taxes (municipal,
state, and federal) which may now or hereafter be imposed upon the ownership,
leasing, renting, possession, sale, or use of the Collateral, other than taxes
on or measured by the Lender's income and fees, assessments, charges, and taxes
which are being contested in good faith by appropriate proceedings diligently
conducted and with respect to which adequate reserves are maintained to the
extent required by GAAP.

          SECTION  5.7.  NO CHANGE OF LOCATION, STRUCTURE, OR IDENTITY.  The
Borrower will not (a) change the location of its chief executive office or
establish any place of business other than those specified herein or (b) move or
permit the movement of any item of Collateral from the location specified in the
applicable Schedule, except that the Borrower may change its chief executive
office and keep Collateral at other locations within the United States provided
that the Borrower has delivered to the Lender (i) prior written notice thereof
and (ii) duly executed financing statements and other agreements and instruments
(all in form and substance satisfactory to the Lender) necessary or, in the
opinion of the Lender, desirable to perfect and maintain in favor of the Lender
a first priority security interest in the Collateral.  Notwithstanding anything
to the contrary in the immediately preceding sentence, the Borrower may keep any
Collateral consisting of motor vehicles or rolling stock at any location in the
United States provided that the Lender's security interest in any such
Collateral is conspicuously marked on the certificate of title thereof and the
Borrower has complied with the provisions of Section 5.9.

          SECTION 5.8.   USE OF COLLATERAL; LICENSES; REPAIR.  The Collateral
shall be operated by competent, qualified personnel in connection with the
Borrower's business purposes, for the purpose for which the Collateral was
designed and in accordance with applicable operating instructions, laws, and
government regulations, and the Borrower shall use every reasonable precaution
to prevent loss or damage to the Collateral from fire and other hazards.  The
Collateral shall not be used or operated for personal, family, or household
purposes.  The Borrower shall procure and maintain in effect all orders,
licenses, certificates, permits, approvals, and consents required by federal,
state, or local laws or by any governmental body, agency, or authority in
connection with the delivery, installation, use, and operation of the
Collateral.  The Borrower shall keep all of the Equipment in a satisfactory
state of repair and satisfactory operating condition in accordance with industry
standards, and will make all repairs and replacements when and where necessary
and practical.  The Borrower will not waste or destroy the Equipment or any part
thereof, and will not be negligent in the care or use thereof.  Except in the
case of tenant improvements, the Equipment shall not be annexed or affixed to or
become part of any realty without the Lender's prior written consent.

          SECTION 5.9.   FURTHER ASSURANCES.  The Borrower will, promptly upon
request by the Lender, execute and deliver or use its best efforts to obtain any
document required by the Lender (including, 

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without limitation, warehouseman or processor disclaimers, mortgagee waivers, 
landlord disclaimers, or subordination agreements with respect to the 
Obligations and the Collateral), give any notices, execute and file any 
financing statements, mortgages, or other documents (all in form and 
substance satisfactory to the Lender), mark any chattel paper, deliver any 
chattel paper or instruments to the Lender, and take any other actions that 
are necessary or, in the opinion of the Lender, reasonably desirable to 
perfect or continue the perfection and the first priority of the Lender's 
security interest in the Collateral, to protect the Collateral against the 
rights, claims, or interests of any Persons, or to effect the purposes of 
this Agreement.  The Borrower hereby authorizes the Lender to file one or 
more financing or continuation statements, and amendments thereto, relating 
to all or any part of the Collateral without the signature of the Borrower 
where permitted by law.  A carbon, photographic, or other reproduction of 
this Agreement or any financing statement covering the Collateral or any part 
thereof shall be sufficient as a financing statement where permitted by law.  
To the extent required under this Agreement, the Borrower will pay all costs 
incurred in connection with any of the foregoing.

          SECTION 5.10.  NO DISPOSITION OF COLLATERAL.  The Borrower will not in
any way hypothecate or create or permit to exist any lien, security interest,
charge, or encumbrance on or other interest in any of the Collateral, except for
the lien and security interest granted hereby and Permitted Liens which are
junior to the lien and security interest of the Lender, and the Borrower will
not sell, transfer, assign, pledge, collaterally assign, exchange, or otherwise
dispose of any of the Collateral.  In the event the Collateral, or any part
thereof, is sold, transferred, assigned, exchanged, or otherwise disposed of in
violation of these provisions, the security interest of the Lender shall
continue in such Collateral or part thereof notwithstanding such sale, transfer,
assignment, exchange, or other disposition, and the Borrower will hold the
proceeds thereof in a separate account for the benefit of the Lender.  Following
such a sale, the Borrower will transfer such proceeds to the Lender in kind.

          SECTION 5.11.  NO LIMITATION ON LENDER'S RIGHTS.  The Borrower will
not enter into any contractual obligations which may restrict or inhibit the
Lender's rights or ability to sell or otherwise dispose of the Collateral or any
part thereof.

          SECTION 5.12.  PROTECTION OF COLLATERAL.  Upon notice to the Borrower
(provided that if an Event of Default has occurred and is continuing the Lender
need not give any notice), the Lender shall have the right at any time to make
any payments and do any other acts the Lender may deem necessary to protect its
security interests in the Collateral, including, without limitation, the rights
to satisfy, purchase, contest, or compromise any encumbrance, charge, or lien
which, in the reasonable judgment of the Lender, appears to be prior to or
superior to the security interests granted hereunder, and appear in, and defend
any action or proceeding purporting to affect its security interests in, or the
value of, any of the Collateral.  The Borrower hereby agrees to reimburse the
Lender for all payments made and expenses incurred under this Agreement
including fees, expenses, and disbursements of attorneys and paralegals acting
for the Lender, including any of the foregoing payments under, or acts taken to
protect its security interests in, any of the Collateral, which amounts shall be
secured under this Agreement, and agrees it shall be bound by any payment made
or act taken by the Lender hereunder absent the Lender's gross negligence or
willful misconduct.  The Lender shall have no obligation to make any of the
foregoing payments or perform any of the foregoing acts.

          SECTION 5.13.  DELIVERY OF ITEMS.  The Borrower will (a) promptly (but
in no event later than three Business Days) after its receipt thereof, deliver
to the Lender any documents or certificates of title issued with respect to any
property included in the Collateral, and any promissory notes, letters of credit
or instruments related to or otherwise in connection with any property included
in the Collateral, which in any such case come into the possession of the
Borrower, or shall cause the issuer thereof to deliver any of the same directly
to the Lender, in each case with any necessary endorsements in favor of the
Lender and (b) deliver to the Lender as soon as available copies of any and all
press releases and other similar communications issued by the Borrower.

          SECTION 5.14.  SOLVENCY.  The Borrower shall be and remain Solvent at
all times.

          SECTION 5.15.  FUNDAMENTAL CHANGES.  The Borrower shall not (a) amend
or modify its name, unless the Borrower delivers to the Lender thirty days prior
to any such proposed amendment or modification written notice of such amendment
or modification and within ten days before such amendment or 

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<PAGE>

modification delivers executed Uniform Commercial Code financing statements 
(in form and substance satisfactory to the Lender) or (b) merge or 
consolidate with any other entity, in each case without the Lender's prior 
written consent which shall not be unreasonably withheld.

          SECTION 5.16.  ADDITIONAL REQUIREMENTS.  The Borrower shall take all
such further actions and execute all such further documents and instruments as
the Lender may reasonably request.

     SECTION 6. FINANCIAL STATEMENTS.  Until the payment and satisfaction in
full of all Obligations, the Borrower shall deliver to the Lender the following
financial information:

          SECTION 6.1.   ANNUAL FINANCIAL STATEMENTS.  As soon as available, but
not later than 120 days after the end of each fiscal year of the Borrower and
its consolidated subsidiaries, the consolidated balance sheet, income statement,
and statements of cash flows and shareholders equity for the Borrower and its
consolidated subsidiaries (the "Financial Statements") for such year, reported
on by independent certified public accountants without an adverse qualification;
and

          SECTION 6.2.   QUARTERLY FINANCIAL STATEMENTS.  As soon as available,
but not later than 60 days after the end of each of the first three fiscal
quarters in any fiscal year of the Borrower and its consolidated subsidiaries,
the Financial Statements for such fiscal quarter, together with a certification
duly executed by a responsible officer of the Borrower that such Financial
Statements have been prepared in accordance with GAAP and are fairly stated in
all material respects (subject to normal year-end audit adjustments).

     SECTION 7. EVENTS OF DEFAULT.  The occurrence of any of the following
events shall constitute an Event of Default hereunder:

          (a)   the Borrower shall fail to pay within five days of when due any
amount required to be paid by the Borrower under or in connection with any Note
and this Agreement; 

          (b)   any representation or warranty made or deemed made by the
Borrower under or in connection with any Loan Document or any Financial
Statement shall prove to have been false or incorrect in any material respect
when made;

          (c)   the Borrower shall fail to perform or observe (i) any of the
terms, covenants or agreements contained in Sections 5.4, 5.7, 5.10, 5.14, or
5.15 hereof or (ii) any other term, covenant, or agreement contained in any Loan
Document (other than the other Events of Default specified in this Section 7)
and such failure remains unremedied for the earlier of fifteen days from (A) the
date on which the Lender has given the Borrower written notice of such failure
and (B) the date on which the Borrower knew of such failure; 

          (d)   any provision of any Loan Document to which the Borrower is a
party shall for any reason cease to be valid and binding on the Borrower, or the
Borrower shall so state;

          (e)   dissolution, liquidation, winding up, or cessation of the
Borrower's business, failure of the Borrower generally to pay its debts as they
mature, admission in writing by the Borrower of its inability generally to pay
its debts as they mature, or calling of a general meeting of the Borrower's
creditors generally for purposes of compromising any of the Borrower's debts;
the compromise of bona fide disputes shall not be deemed to be compromises
hereunder;

          (f)   the commencement by or against the Borrower of any bankruptcy,
insolvency, arrangement, reorganization, receivership, or similar proceedings
under any federal or state law and, in the case of any such involuntary
proceeding, such proceeding remains undismissed or unstayed for forty-five days
following the commencement thereof, or any action by the Borrower is taken
authorizing any such proceedings;

          (g)   an assignment for the benefit of creditors is made by the
Borrower, whether voluntary or involuntary, the appointment of a trustee,
custodian, receiver, or similar official for the Borrower or for 

                                       9

<PAGE>

any substantial property of the Borrower, or any action by the Borrower 
authorizing any such proceeding;

          (h)   the Borrower shall default in (i) the payment of principal or
interest on any indebtedness in excess of $100,000 (other than the Obligations)
beyond the period of grace, if any, provided in the instrument or agreement
under which such indebtedness was created; or (ii) the observance or performance
of any other agreement or condition relating to any such indebtedness or
contained in any instrument or agreement relating thereto, or any other event
shall occur or condition exist, the effect of which default or other event or
condition is to cause, or to permit the holder or holders of such indebtedness
to cause, with the giving of notice if required, such indebtedness to become due
prior to its stated maturity; or (iii) any loan or other agreement under which
the Borrower has received financing from Transamerica Corporation or any of its
affiliates;

          (i)   the Borrower suffers or sustains a Material Adverse Change;

          (j)   any tax lien, other than a Permitted Lien, is filed of record
against the Borrower and is not bonded or discharged within five Business Days;

          (k)   any judgment which has had or could reasonably be expected to
have a Material Adverse Effect on the Borrower and such judgment shall not be
stayed, vacated, bonded, or discharged within sixty days;

          (l)   any material covenant, agreement, or obligation, as determined
in the sole discretion of the Lender, made by the Borrower and contained in or
evidenced by any of the Loan Documents shall cease to be enforceable, or shall
be determined to be unenforceable, in accordance with its terms; the Borrower
shall deny or disaffirm the Obligations under any of the Loan Documents or any
liens granted in connection therewith; or any liens granted on any of the
Collateral in favor of the Lender shall be determined to be void, voidable, or
invalid, or shall not be given the priority contemplated by this Agreement; or

          (m)   there is a change, which change results from a single
transaction or series of related transactions, but not from the sale of newly
issued securities to investors, in more than 35% of the ownership of any equity
interests of the Borrower on the date hereof or more than 35% of such interests
become subject to any contractual, judicial, or statutory lien, charge, security
interest, or encumbrance.  

     SECTION 8. REMEDIES.  If any Event of Default shall have occurred and be
continuing:

          (a)   The Lender may, without prejudice to any of its other rights
under any Loan Document or Applicable Law, declare all Obligations to be
immediately due and payable (except with respect to any Event of Default set
forth in Section 7(f) hereof, in which case all Obligations shall automatically
become immediately due and payable without necessity of any declaration) without
presentment, representation, demand of payment, or protest, which are hereby
expressly waived.

          (b)   The Lender, during Borrower's normal business hours, may take
possession of the Collateral and, for that purpose may enter, with the aid and
assistance of any person or persons, any premises where the Collateral or any
part hereof is, or may be placed, and remove the same.  The Lender hereby
acknowledges the use of hazardous materials at the premises where the Collateral
is located and hereby accepts complete responsibility and liability for any
personal injury, property damage, or damage to the environment resulting
directly from the Borrower within the premises and removing any of the
Collateral.

          (c)   The obligation of the Lender, if any, to make additional Loans
or financial accommodations of any kind to the Borrower shall immediately
terminate.

          (d)   The Lender may exercise in respect of the Collateral, in
addition to other rights and remedies provided for herein (or in any Loan
Document) or otherwise available to it, all the rights and remedies of a secured
party under the applicable Uniform Commercial Code (the "Code") whether or not
the Code applies to the affected Collateral and also may (i) require the
Borrower to, and the Borrower hereby agrees that it will at its 

                                       10

<PAGE>

expense and upon request of the Lender forthwith, assemble all or part of the 
Collateral as directed by the Lender and make it available to the Lender at 
a place to be designated by the Lender that is reasonably convenient to both 
parties and (ii) without notice except as specified below, sell the 
Collateral or any part thereof in one or more parcels at public or private 
sale, at any of the Lender's offices or elsewhere, for cash, on credit, or 
for future delivery, and upon such other terms as the Lender may deem 
commercially reasonable.  The Borrower agrees that, to the extent notice of 
sale shall be required by law, at least ten days' notice to the Borrower of 
the time and place of any public sale or the time after which any private 
sale is to be made shall constitute reasonable notification.  The Lender 
shall not be obligated to make any sale of Collateral regardless of notice of 
sale having been given.  The Lender may adjourn any public or private sale 
from time to time by announcement at the time and place fixed therefor, and 
such sale may, without further notice, be made at the time and place to which 
it was so adjourned.

          (e)   All cash proceeds received by the Lender in respect of any sale
of, collection from, or other realization upon all or any part of the Collateral
may, in the discretion of the Lender, be held by the Lender as collateral for,
or then or at any time thereafter applied in whole or in part by the Lender
against, all or any part of the Obligations in such order as the Lender shall
elect.  Any surplus of such cash or cash proceeds held by the Lender and
remaining after the full and final payment of all the Obligations shall be paid
over to the Borrower or to such other Person to which the Lender may be required
under applicable law, or directed by a court of competent jurisdiction, to make
payment of such surplus.

     SECTION 9.  MISCELLANEOUS PROVISIONS.  

          SECTION 9.1.   NOTICES.  Except as otherwise provided herein, all
notices, approvals, consents, correspondence, or other communications required
or desired to be given hereunder shall be given in writing and shall be
delivered by overnight courier, hand delivery, or certified or registered mail,
postage prepaid, if to the Lender, then to Transamerica Technology Finance
Division, 76 Batterson Park Road, Farmington, Connecticut 06032, Attention: 
Assistant Vice President, Lease Administration, with a copy to the Lender at
Riverway II, West Office Tower, 9399 West Higgins Road, Rosemont, Illinois 
60018, Attention:  Legal Department, and if to the Borrower, then to Trega
Biosciences, Inc., 9880 Campus Point Drive, San Diego, California  92121,
Attention: Acting Chief Financial Officer or such other address as shall be
designated by the Borrower or the Lender to the other party in accordance
herewith.  All such notices and correspondence shall be effective when received.

          SECTION  9.2.  HEADINGS.  The headings in this Agreement are for
purposes of reference only and shall not affect the meaning or construction of
any provision of this Agreement.

          SECTION 9.3.   ASSIGNMENTS.  Except in connection with transactions to
which Lender has consented, the Borrower shall not have the right to assign any
Note or this Agreement or any interest therein unless the Lender shall have
given the Borrower prior written consent and the Borrower and its assignee shall
have delivered assignment documentation in form and substance satisfactory to
the Lender in its sole discretion.  The Lender may assign its rights and
delegate its obligations under any Note or this Agreement.

          SECTION 9.4.   AMENDMENTS, WAIVERS, AND CONSENTS.  Any amendment or
waiver of any provision of this Agreement and any consent to any departure by
the Borrower from any provision of this Agreement shall be effective only by a
writing signed by the Lender and shall bind and benefit the Borrower and the
Lender and their respective successors and assigns, subject, in the case of the
Borrower, to the first sentence of Section 9.3.

          SECTION 9.5.   INTERPRETATION OF AGREEMENT.  Time is of the essence in
each provision of this Agreement of which time is an element.  All terms not
defined herein or in a Note shall have the meaning set forth in the applicable
Code, except where the context otherwise requires.  To the extent a term or
provision of this Agreement conflicts with any Note, or any term or provision
thereof, and is not dealt with herein with more specificity, this Agreement
shall control with respect to the subject matter of such term or provision. 
Acceptance of or acquiescence in a course of performance rendered under this
Agreement shall not be relevant in determining the meaning of this Agreement
even though the accepting or acquiescing party had knowledge of the nature of
the performance and opportunity for objection.

                                       11

<PAGE>

          SECTION 9.6.   CONTINUING SECURITY INTEREST.  This Agreement shall
create a continuing security interest in the Collateral and shall (i) remain in
full force and effect until the indefeasible payment in full of the Obligations,
(ii) be binding upon the Borrower and its successors and assigns and
(iii) inure, together with the rights and remedies of the Lender hereunder, to
the benefit of the Lender and its successors, transferees, and assigns.

          SECTION 9.7.   REINSTATEMENT.  To the extent permitted by law, this
Agreement and the rights and powers granted to the Lender hereunder and under
the Loan Documents shall continue to be effective or be reinstated if at any
time any amount received by the Lender in respect of the Obligations is
rescinded or must otherwise be restored or returned by the Lender upon the
insolvency, bankruptcy, dissolution, liquidation, or reorganization of the
Borrower or upon the appointment of any receiver, intervenor, conservator,
trustee, or similar official for the Borrower or any substantial part of its
assets, or otherwise, all as though such payments had not been made.

          SECTION 9.8.   SURVIVAL OF PROVISIONS.  All representations,
warranties, and covenants of the Borrower contained herein shall survive the
execution and delivery of this Agreement, and shall terminate only upon the full
and final payment and performance by the Borrower of the Obligations secured
hereby.

          SECTION 9.9.   INDEMNIFICATION.  The Borrower agrees to indemnify and
hold harmless the Lender and its directors, officers, agents, employees, and
counsel from and against any and all costs, expenses, claims, or liability
incurred by the Lender or such Person hereunder and under any other Loan
Document or in connection herewith or therewith, unless such claim or liability
shall be due to willful misconduct or gross negligence on the part of the Lender
or such Person.

          SECTION 9.10.  COUNTERPARTS; TELECOPIED SIGNATURES.  This Agreement
may be executed in counterparts, each of which when so executed and delivered
shall be an original, but both of which shall together constitute one and the
same instrument.  This Agreement and each of the other Loan Documents and any
notices given in connection herewith or therewith may be executed and delivered
by telecopier or other facsimile transmission all with the same force and effect
as if the same was a fully executed and delivered original manual counterpart.

          SECTION 9.11.  SEVERABILITY.  In case any provision in or obligation
under this Agreement or any Note or any other Loan Document shall be invalid,
illegal, or unenforceable in any jurisdiction, the validity, legality, and
enforceability of the remaining provisions or obligations, or of such provision
or obligation in any other jurisdiction, shall not in any way be affected or
impaired thereby.

          SECTION 9.12.  DELAYS; PARTIAL EXERCISE OF REMEDIES.  No delay or
omission of the Lender to exercise any right or remedy hereunder, whether before
or after the happening of any Event of Default, shall impair any such right or
shall operate as a waiver thereof or as a waiver of any such Event of Default. 
No single or partial exercise by the Lender of any right or remedy shall
preclude any other or further exercise thereof, or preclude any other right or
remedy.

          SECTION 9.13.  ENTIRE AGREEMENT.  The Borrower and the Lender agree
that this Agreement, the Schedule hereto, and the Commitment Letter are the
complete and exclusive statement and agreement between the parties with respect
to the subject matter hereof, superseding all proposals and prior agreements,
oral or written, and all other communications between the parties with respect
to the subject matter hereof.  Should there exist any inconsistency between the
terms of the Commitment Letter and this Agreement, the terms of this Agreement
shall prevail.

          SECTION 9.14.  SETOFF.  In addition to and not in limitation of all
rights of offset that the Lender may have under Applicable Law, and whether or
not the Lender has made any demand or the Obligations of the Borrower have
matured, the Lender shall have the right to appropriate and apply to the payment
of the Obligations of the Borrower all deposits and other obligations then or
thereafter owing by the Lender to or for the 

                                       12

<PAGE>

credit or the account of the Borrower.  

          SECTION 9.15.  WAIVER OF JURY TRIAL.   THE BORROWER AND THE LENDER
IRREVOCABLY WAIVE ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING, OR
COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS AGREEMENT, ANY OTHER LOAN
DOCUMENT, OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY.

          SECTION 9.16.  GOVERNING LAW. THE VALIDITY, INTERPRETATION, AND
ENFORCEMENT OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF ILLINOIS WITHOUT GIVING EFFECT TO THE CONFLICT OF
LAW PRINCIPLES THEREOF.

          SECTION 9.17.  VENUE; SERVICE OF PROCESS.  ANY LEGAL ACTION OR
PROCEEDING WITH RESPECT TO THIS AGREEMENT OR ANY OTHER LOAN DOCUMENT MAY BE
BROUGHT IN THE COURTS OF THE STATE OF ILLINOIS SITUATED IN COOK COUNTY, OR OF
THE UNITED STATES OF AMERICA FOR THE NORTHERN DISTRICT OF ILLINOIS, AND, BY
EXECUTION AND DELIVERY OF THIS AGREEMENT, THE BORROWER HEREBY ACCEPTS FOR ITSELF
AND IN RESPECT OF ITS PROPERTY, GENERALLY AND UNCONDITIONALLY, THE JURISDICTION
OF THE AFORESAID COURTS.  THE BORROWER HEREBY IRREVOCABLY WAIVES, IN CONNECTION
WITH ANY SUCH ACTION OR PROCEEDING, (a) ANY OBJECTION, INCLUDING, WITHOUT
LIMITATION, ANY OBJECTION TO THE LAYING OF VENUE OR BASED ON THE GROUNDS OF
FORUM NON CONVENIENS, THAT IT MAY NOW OR HEREAFTER HAVE TO THE BRINGING OF ANY
SUCH ACTION OR PROCEEDING IN SUCH RESPECTIVE JURISDICTIONS AND (b) THE RIGHT TO
INTERPOSE ANY NONCOMPULSORY SETOFF, COUNTERCLAIM, OR CROSS-CLAIM.  THE BORROWER
IRREVOCABLY CONSENTS TO THE SERVICE OF PROCESS OF ANY OF THE AFOREMENTIONED
COURTS IN ANY SUCH ACTION OR PROCEEDING BY THE MAILING OF COPIES THEREOF BY
REGISTERED OR CERTIFIED MAIL, POSTAGE PREPAID, TO THE BORROWER AT THE ADDRESS
FOR IT SPECIFIED IN SECTION 9.1 HEREOF.  NOTHING HEREIN SHALL AFFECT THE RIGHT
OF THE LENDER TO SERVE PROCESS IN ANY OTHER MANNER PERMITTED BY LAW OR TO
COMMENCE LEGAL PROCEEDINGS OR OTHERWISE PROCEED AGAINST THE BORROWER IN ANY
OTHER JURISDICTION, SUBJECT IN EACH INSTANCE TO THE PROVISIONS HEREOF WITH
RESPECT TO RIGHTS AND REMEDIES.

          IN WITNESS WHEREOF, the undersigned Borrower has caused this Agreement
to be duly executed and delivered by its proper and duly authorized officer as
of the date first set forth above.

                         TREGA BIOSCIENCES, INC.


                         By:  /s/ Lawrence D. Muschek
                              -----------------------
                            Name: Lawrence D. Muschek
                            Title:  President, Research & Development
                         Federal Tax ID:  51-0336233

Accepted as of the 
23 day of December, 1998


TRANSAMERICA BUSINESS CREDIT CORPORATION

By:  /s/ Gary P. Moro
   ----------------------
   Name: Gary P. Moro
   Title:  Vice President


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