EXHIBIT 10.38.1

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. I)




                                     - 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. I)

     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.  I, 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.  16735202  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.  16735208 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.  16735205  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  pages  four and five 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  TWENTY-NINE  MILLION  EIGHT  HUNDRED
     ELEVEN THOUSAND THREE HUNDRED SIXTY-NINE Dollars ($29,811,369.00),  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  Twenty-Three   Million  One  Hundred  Forty-Two  Thousand  Six  Hundred
     Thirty-One Dollars ($23,142,631.00) 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 amended and restated as follow:

          "Notes:  The Promissory Note 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 the Promissory
     Note of dated January 3, 2008 executed by Mission West Properties, L.P. II,
     a Delaware  limited  partnership 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,  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 5 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 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,
     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 herein 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. I, 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
                                        &
                         First Priority Lien Instrument
                                        &
                       First Priority Absolute Assignment

                                   Exhibit "A"

                                (Mission West I)


                               Valley Green Drive


PARCEL ONE:

PARCEL 3 AS SHOWN ON THAT CERTAIN  PARCEL MAP RECORDED  AUGUST 9, 1974,  IN BOOK
344, PAGE 10, SANTA CLARA COUNTY.

EXCEPTING  THEREFROM THE UNDERGROUND WATER RIGHTS, BUT WITHOUT SURFACE RIGHTS OF
ENTRY, AS GRANTED TO THE CITY OF CUPERTINO BY INTRUMENT RECORDED JANUARY 3, 1975
IN BOOK B233 OF OFFICIAL RECORDS AT PAGE 276.


PARCEL TWO:

AN EASEMENT FOR INGRESS AND EGRESS AND FOR THE INSTALLATION AND MAINTENANCE OF A
PUBLIC UTILITIES OVER THE WESTERLY 15 FEET OF PARCELS 1 AND 2 AND THE EASTERLY
15 FEET OF PARCEL 4, AS SAID PARCELS ARE SHOWN ON THAT CERTAIN PARCEL MAP
RECORDED AUGUST 9, 1974 IN BOOK 344 AT PAGE 10 OF MAPS, RECORDS OF SANTA CLARA
COUNTY, CALIFORNIA

ASSESSORS PARCEL NO:  326-10-046


                                     - 7 -
<PAGE>


                         First Priority Lien Instrument
                                        &
                         First Priority Lien Instrument

                                   Exhibit "B"


                                     - 8 -