EXHIBIT 10.40.1

RECORDING REQUESTED BY
   Northwestern Mutual Life

When Recorded Mail to:

The Northwestern Mutual Life
Insurance Company
Nadine T. Hansohn - Room N16WC
720 E. Wisconsin Avenue
Milwaukee, WI 53202

Loan No. 332757





                        FIRST AMENDMENT TO DEED OF TRUST
                     AND SECURITY AGREEMENT (FIRST PRIORITY)
                                       AND
                        FIRST AMENDMENT TO DEED OF TRUST
                    AND SECURITY AGREEMENT (SECOND PRIORITY)
                                       AND
                     FIRST AMENDMENT TO ABSOLUTE ASSIGNMENT
                               OF LEASES AND RENTS
                       (Mission West Properties, L.P. II)

                                     - 1 -
<PAGE>


RECORDING REQUESTED BY



WHEN RECORDED MAIL TO

The Northwestern Mutual Life Ins. Co.
720 East Wisconsin Avenue - Rm N16WC
Milwaukee, WI 53202
Attn:  Nadine T. Hansohn
Loan No. 332757           SPACE ABOVE THIS LINE FOR RECORDER'S USE

  FIRST AMENDMENT TO DEED OF TRUST AND SECURITY AGREEMENT (FIRST PRIORITY) AND
             FIRST AMENDMENT TO DEED OF TRUST AND SECURITY AGREEMENT
                              (SECOND PRIORITY) AND
           FIRST AMENDMENT TO ABSOLUTE ASSIGNMENT OF LEASES AND RENTS
                       (Mission West Properties, L.P. II)

     THIS  FIRST  AMENDMENT  TO DEED OF  TRUST  AND  SECURITY  AGREEMENT  (First
Priority) AND FIRST  AMENDMENT TO DEED OF TRUST AND SECURITY  AGREEMENT  (Second
Priority)  AND THIS FIRST  AMENDMENT TO ABSOLUTE  ASSIGNMENT OF LEASES AND RENTS
(this  "First  Amendment"),  is  made  and  entered  into  as of the  5th day of
November,  2008 by and between  MISSION  WEST  PROPERTIES,  L.P.  II, a Delaware
limited  partnership,  10050 Bandley Drive,  Cupertino,  CA 95014, herein called
"Borrower",   THE  NORTHWESTERN  MUTUAL  LIFE  INSURANCE  COMPANY,  a  Wisconsin
corporation,  720 East Wisconsin  Avenue,  Milwaukee,  Wisconsin  53202,  herein
called "Lender":

                                    RECITALS

     A. Borrower has previously executed that certain Deed of Trust and Security
Agreement  (First  Priority) (the "First Priority Lien  Instrument") in favor of
Lender,  dated January 3, 2003 executed by Borrower and recorded January 9, 2003
as  Document  No.  16735209  in the  Official  Records  of Santa  Clara  County,
California,  covering  certain real  property  (the  "Property")  located in the
County of Santa Clara,  State of California and more  particularly  described in
Exhibit A attached thereto.

     B. Borrower has previously executed that certain Deed of Trust and Security
Agreement  and  Assignment of Leases and Rents  (Second  Priority)  (the "Second
Priority  Lien  Instrument")  in favor of  Lender,  dated  January  3,  2003 and
recorded  January 9, 2003 as Document No.  16735203 in the  Official  Records of
Santa Clara County, California, covering the Property.

     C. Borrower has  previously  executed that certain  Absolute  Assignment of
Leases and Rents  (First  Priority)  (the  "Assignment  of Leases and Rents") in
favor of Lender,  dated January 3, 2008 and recorded January 9, 2003 as Document
No.  16735206  in the  Official  Records  of  Santa  Clara  County,  California,
assigning the leases and rents for the Property.

     D. The  parties  hereto  desire to enter in this  First  Amendment  for the
purpose of amending the First Priority Lien Instrument, the Second Priority Lien
Instrument and the Assignment of Leases and Rents.

     NOW,  THEREFORE,  in consideration of the foregoing facts and the covenants
contained  herein and other  valuable  consideration  receipt of which is hereby
acknowledged, Borrower and Lender hereby agree as follows:

     1. Unless otherwise defined herein,  words and terms used herein shall have
the same meaning as defined in the First  Priority Lien  Instrument,  the Second
Priority Lien Instrument and the Assignment of Leases and Rents.

     2. That Exhibit "A", Legal Description, attached to the First Priority Lien
Instrument shall be deleted and replaced with Exhibit "A" attached hereto.

                                     - 2 -
<PAGE>

     3. That Exhibit "B",  Facilities List,  attached to the First Priority Lien
Instrument shall be deleted and replaced with the Exhibit "B" attached hereto.

     4. That the  definition  of "Note "on page four of the First  Priority Lien
Instrument is hereby amend and restated as follow:

          "Note:  The Promissory  Note dated January 3, 2003 executed by Grantor
     in the  original  principal  amount  of  FORTY-ONE  MILLION  THREE  HUNDRED
     NINETEEN  THOUSAND  NINE  HUNDRED  SEVENTY-SIX  Dollars   ($41,319,976.00),
     payable to  Beneficiary  or its order,  with final  maturity  no later than
     February 1, 2013, as amended by that certain First  Amendment to Promissory
     Note  dated  November  4,  2008,  amending  the  principal  amount  of  the
     Promissory  Note to be Nine  Million Five Hundred  Fifteen  Thousand  Eight
     Hundred Seventy-Seven Dollars ($9,515,877.00), and with interest as therein
     expressed, and all modifications, renewals or extensions of such Promissory
     Note."


     5. That Exhibit "A",  Legal  Description,  attached to the Second  Priority
Lien  Instrument  shall be deleted and  replaced  with the Exhibit "A"  attached
hereto.

     6. That Exhibit "B",  Facilities List, attached to the Second Priority Lien
Instrument shall be deleted and replace with the Exhibit "B" attached hereto.

     7. That the  definition  of  "Notes"  on pages  four and five of the Second
Priority Lien Instrument is hereby amend and restated as follow:

          "Notes:  The Promissory Note dated January 3, 2008 executed by Mission
     West  Properties,  L.P. I, a Delaware  limited  partnership in the original
     principal amount of Twenty Nine Million Eight Hundred Eleven Thousand Three
     Hundred  Sixty-Nine  Dollars  ($29,811,369.00)  as amended by that  certain
     First  Amendment To Promissory  Note dated  November 4, 2008,  amending the
     principal  balance of such Promissory  Note to be Twenty-Three  Million One
     Hundred Forty-Two Thousand Six Hundred Thirty-One Dollars ($23,142,631.00),
     payable to  Beneficiary  or its  order,  and the  Promissory  Note of dated
     January 3, 2008  executed  by Mission  West  Properties,  L.P.,  a Delaware
     limited  partnership  in the  original  principal  amount of  Twenty  Eight
     Million Eight Hundred  Sixty-Eight  Thousand Six Hundred Fifty-Five Dollars
     ($28,868,655.00)  as amended by that certain First  Amendment To Promissory
     Note  dated  November  4,  2008,  amending  the  principal  balance of such
     Promissory Note to be Forty-Eight Million Nine Hundred Sixty-Eight Thousand
     Five Hundred Forty-One Dollars ($48,968,541.00),  payable to Beneficiary or
     its order,  and each with final maturity no later than February 1, 2013 and
     with  interest as therein  expressed,  and all  modifications,  renewals or
     extensions of such Promissory Notes."


     8. That the definition of "Other Note" on page five of the Second  Priority
Lien Instrument is hereby amend and restated as follow:

          "Other Note:  The  Promissory  Note dated  January 3, 2003 executed by
     Grantor in the original principal amount of Forty One Million Three Hundred
     Nineteen  Thousand Nine Hundred  Seventy-Six  Dollars  ($41,319,976.00)  as
     amended by that certain First  Amendment To Promissory  Note dated November
     4, 2008,  amending the principal balance of such Promissory Note to be Nine
     Million Five Hundred Fifteen Thousand Eight Hundred  Seventy-Seven  Dollars
     ($9,515,877.00),  payable to Beneficiary or its order,  with final maturity
     no later than February 1, 2013 and with interest as therein expressed,  and
     all modifications, renewals or extensions of such Promissory Note."

     9. That Exhibit  "A",  Legal  Description,  attached to the  Assignment  of
Leases and Rents shall  deleted  and  replaced  with the  Exhibit  "A"  attached
hereto.

     10. That except as hereby amended the said First Priority Lien  Instrument,
the Second Priority Lien Instrument and the Assignment of Leases and Rents shall
remain in full force and effect,  unchanged  and in all  respects,  ratified and
confirmed.

                                     - 3 -
<PAGE>

     11. That nothing  herein  contained  shall affect the priority of the First
Priority Lien Instrument,  the Second Priority Lien Instrument or the Assignment
of Leases and Rents over other liens,  charges,  encumbrances or conveyances nor
shall it release or change the  liability  of any party who may now or hereafter
be liable,  primarily or secondarily,  under or on account of the Note, Notes or
Other Notes, as hereinafter defined.






                (Remainder of the page intentionally left blank)

                                     - 4 -
<PAGE>


IN WITNESS WHEREOF, this First Amendment has been executed by the undersigned as
of the date and year first above written.

                              THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY,
                              a Wisconsin corporation

                              By:    Northwestern Investment Management Company,
                                     LLC, a Delaware limited liability company,
                                     its wholly-owned affiliate and authorized
                                     representative

                                     By:        /S/ Michael P. Cusick
                                        ----------------------------------------
                                        Michael P. Cusick
                                        Managing Director

                                     Attest:    /S/ Donna L. Lemanczyk
                                            ------------------------------------
                                            Donna L. Lemanczyk
                                            Assistant Secretary

                                             CALIFORNIA ACKNOWLEDGMENT
                                                  ALL-PURPOSE
STATE OF WISCONSIN              )
                                )ss.
COUNTY OF MILWAUKEE             )

On November 5, 2008, before me, Janet M. Szukalski, a Notary Public,  personally
appeared Michael P. Cusick and Donna L. Lemanczyk, who proved to me on the basis
of  satisfactory  evidence to be the persons  whose names are  subscribed to the
within  instrument and  acknowledged  to me that they executed the same in their
authorized  capacities,  and  that by their  signatures  on the  instrument  the
persons,  or the entity  upon behalf of which the persons  acted,  executed  the
instrument.

I certify  under  PENALTY OF PERJURY  under the laws of the State of  California
that the foregoing paragraph is true and correct.

                               WITNESS my hand and official seal.

                               Signature         /S/ Janet M. Szukalski
                                        ----------------------------------------
                                        Janet M. Szukalski
(Place Notary Seal Above)               Name (typed or printed)
                                        My Commission expires:  April 22, 2012

                                     - 5 -
<PAGE>



                               MISSION WEST PROPERTIES, L.P. II,
                               a Delaware limited partnership

                               By:      Mission West Properties, Inc.,
                                        a Maryland corporation, its general
                                        partner

                                        By:      /S/ Raymond V. Marino
                                           -------------------------------------
                                        Name:    Raymond V. Marino
                                             -----------------------------------
                                        Title:   President & COO
                                              ----------------------------------


                                    CALIFORNIA ACKNOWLEDGMENT
                                         ALL-PURPOSE
STATE OF California           )
                              )ss.
COUNTY OF   Santa Clara       )

On November 7, 2008 , before me, Vanessa  Almanza , a Notary Public,  personally
appeared  Raymond  V.  Marino , who  proved to me on the  basis of  satisfactory
evidence to be the  person(s)  whose  name(s)  is/are  subscribed  to the within
instrument  and  acknowledged  to me  that  he/she/they  executed  the  same  in
his/her/their authorized capacity(ies),  and that by his/her/their  signature(s)
on the  instrument  the  person(s),  or the  entity  upon  behalf  of which  the
person(s) acted, executed the instrument.

I certify under PENALTY OF PERJURY under the laws of the State of California
that the foregoing paragraph is true and correct.

                                  WITNESS my hand and official seal.

                                  Signature     /S/ Vanessa Almanza
                                           ---------------------------
                                           Vanessa Almanza
(Place Notary Seal Above)                  Name (typed or printed)
                                           My Commission expires: March 29, 2011



This  instrument  was  prepared  by  Brenda  Stugelmeyer,   Attorney,   for  The
Northwestern   Mutual  Life  Insurance  Company,   720  East  Wisconsin  Avenue,
Milwaukee, WI 53202.

                                     - 6 -
<PAGE>


                         First Priority Lien Instrument
                                        &
                         Second Priority Lien Instrument
                                        &
                       First Priority Absolute Assignment


                                   Exhibit "A"

                                (Mission West II)

PROPERTY ONE:

All that certain real property situated in the City of San Jose, County of Santa
Clara, State of California, described as follows:

Parcel  2, as shown on the  Parcel  Map filed  for  record in the  Office of the
Recorder of the County of Santa Clara, State of California on November 26, 1979,
in Book 455 of Maps, Page(s) 1 and 2.

Assessors Parcel No:  706-09-023


PROPERTY TWO:

Parcel 1, as shown on that  Parcel  Map filed  for  record in the  Office of the
Recorder of the County of Santa Clara,  State of  California on May 22, 1980, in
Book 463 of Maps, Page(s) 43 and 44.

Assessors Parcel No:  706-02-034


PROPERTY THREE:

Parcel 7, as shown on that  Parcel  Map filed  for  record in the  Office of the
Recorder of the County of Santa Clara,  State of California on December 5, 1984,
in Book 536 of Maps, Page(s) 41, 42 and 43.

Assessors Parcel No:  086-33-092


PROPERTY FOUR:

Parcel 3 as shown on that  Parcel  Map filed for  recorded  in the Office of the
Recorder of the County of Santa Clara,  State of California on December 5, 1984,
in Book 536 of Maps, Page(s) 41, 42 and 43.

Assessors Parcel No:  086-41-017 & 086-41-018

                                     - 7 -
<PAGE>


                         First Priority Lien Instrument
                                        &
                         Second Priority Lien Instrument


                                   Exhibit "B"


                                     - 8 -