Exhibit 4.5

                           CERTIFICATE OF DESIGNATION

                                       OF

                      CONVERTIBLE PREFERRED STOCK, SERIES E

                                       OF

                                XOMA CORPORATION

                         (Pursuant to Section 151 of the
                        Delaware General Corporation Law)


     XOMA CORPORATION, a corporation organized and existing under the General
Corporation Law of the State of Delaware (the "Corporation"), does hereby
certify that, pursuant to authority conferred upon the Board of Directors of the
Corporation by the Restated Certificate of Incorporation of the Corporation, as
amended, and pursuant to the provisions of Section 151 of the General
Corporation Law of the State of Delaware, said Board of Directors duly adopted
the following resolution on April 18, 1996, which resolution remains in full
force and effect as of the date hereof:

               RESOLVED, that pursuant to the authority granted to and vested in
          the Board of Directors of the Corporation in accordance with the
          provisions of its Amended and Restated Certificate of Incorporation,
          the Board of Directors hereby creates a series of Preferred Stock, par
          value $.05 per share, of the Corporation and hereby states the
          designation and number of shares, and fixes the relative powers,
          preferences, rights, qualifications, limitations and restrictions
          thereof (in addition to the provisions set forth in the Restated
          Certificate of Incorporation of the Corporation, as amended, which are
          applicable to the Preferred Stock of all classes and series), as
          follows:

               Convertible Preferred Stock, Series E:

               Section A. Designation and Amount. Seven Thousand Five Hundred
          (7,500) shares of Preferred Stock, $.05 par value, are designated
          "Convertible Preferred Stock, Series E" with the powers, preferences,
          rights, qualifications, limitations and restrictions specified herein
          (the "Series E Preferred Stock"). Such number of shares may be
          increased or decreased by resolution of the Board of Directors;
          provided, that no decrease shall reduce the number of shares of Series
          E Preferred Stock to a number less than the number of shares then
          outstanding plus the number of shares reserved for issuance upon








               the exercise of outstanding options, rights or warrants or upon
          the conversion of any outstanding securities (including indebtedness)
          issued by the Corporation convertible into Series E Preferred Stock.

               Section B. Dividends.  The  Corporation  shall not be required to
          pay,  and the  holders of the  Series E  Preferred  Stock shall not be
          entitled to receive, any dividends on shares of the Series E Preferred
          Stock.

               Section C. Liquidation, Dissolution or Winding Up. Upon any
          liquidation, dissolution or winding up of the Corporation, whether
          voluntary or involuntary, before any payment or distribution shall be
          made to the holders of shares of the common stock of the Corporation,
          the holders of shares of Series E Preferred Stock shall be entitled to
          receive $10,000.00 per share of Series E Preferred Stock then held by
          such holders, plus an amount equal to declared and unpaid dividends
          and distributions thereon. After payment of the full liquidation
          preference of the Series E Preferred Stock set forth in the preceding
          sentence, the holders of the Series E Preferred Stock shall not be
          entitled to any further payments or distribution from the assets of
          the Corporation.

               Section D. Voting Rights. The holders of shares of Series E
          Preferred Stock shall not have any voting rights, except as required
          under the General Corporation Law of the State of Delaware.

               Section E. Redemption.

               1. General. The Corporation at its option, in accordance with the
          terms and provisions of this Section 5, may, at any time and from time
          to time, redeem any or all shares of Series E Preferred Stock at a
          redemption price per share equal to a cash amount determined by
          multiplying the Conversion Price (as defined below) by the number of
          shares of Common Stock into which each such share of Series E
          Preferred Stock would be convertible pursuant to the provisions of
          Section 6 hereof. If fewer than all the outstanding shares of Series E
          Preferred Stock are to be redeemed, the shares to be redeemed shall be
          selected pro rata as nearly as practicable or by lot, or by such other
          method as the Board of Directors of the Corporation may determine to
          be fair and appropriate.

               2. Notice of Redemption. The Corporation will provide notice of
          any redemption of shares of Series E Preferred Stock to the holders of
          record of the Series E Preferred Stock to be redeemed not less than
          five (5) nor more than sixty (60) days prior to the date fixed for
          such redemption. Such notice shall be provided by first-class mail,
          postage prepaid, to each holder of record of the Series E Preferred
          Stock to be redeemed, at such holder's address as it appears on the
          stock transfer books of the Corporation. Each such notice shall state,
          as appropriate, the following:

                    a. the redemption date;

                    b. the number of shares of  Series E  Preferred  Stock to be
               redeemed and, if fewer than all the shares held by any holder are
               to be  redeemed,  the number of such shares to be  redeemed  from
               such holder;



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                    c. the redemption price;

                    d. the place or places  where  certificates  for such shares
               are to be surrendered for redemption;

                    e. the then effective  Conversion Price (as determined under
               Section 6); and

                    f. that the right of holders to convert shares of Series E
               Preferred Stock to be redeemed will terminate at the close of
               business on the business day next preceding the date fixed for
               redemption (unless the Corporation shall default in the payment
               of the redemption price).

               Any notice that is mailed as set forth above shall be
          conclusively presumed to have been duly given, whether or not the
          holder of shares of Series E Preferred Stock receives such notice, and
          failure to give such notice by mail, or any defect in such notice, to
          the holders of any shares designated for redemption shall not affect
          the validity of the proceedings for the redemption of any other shares
          of Series E Preferred Stock.

               3. Mechanics of Redemption. Upon surrender in accordance with the
          aforesaid notice of the certificate for any shares so redeemed (duly
          endorsed or accompanied by appropriate instruments of transfer), the
          holders of record of such shares shall be entitled to receive the
          redemption price, without interest. In case fewer than all the shares
          represented by such certificate are redeemed, a new certificate
          representing the unredeemed shares shall be issued without cost to the
          holder thereof. Upon surrender of any shares so redeemed in accordance
          with this Section 5(C), the Corporation shall pay the full redemption
          amounts with respect to shares as provided herein.

               4. Rights After Redemption. Notwithstanding that any certificates
          for shares to be redeemed have not been surrendered in accordance with
          Section 5(C), from and after the date of redemption designated in the
          notice of redemption (i) the shares represented thereby shall be
          deemed to be no longer outstanding, and (ii) all rights of the holders
          of such shares of Series E Preferred Stock shall cease and terminate,
          except only the right to receive the full redemption amounts as
          provided herein without interest.

               Section F. Conversion.

               1. Right to Convert. Each share of Series E Preferred Stock shall
          be convertible, at the option of the holder thereof, into that number
          of shares of the Common Stock, par value $.0005 per share, of the
          Corporation (herein, the "Common Stock") as determined by dividing
          $10,000.00 by the Conversion Price (determined as provided below). The
          "Conversion Price" for any shares of Series E Preferred Stock issued
          in connection with a conversion pursuant to Section 4(a) of the
          Convertible Subordinated Note Agreement, dated as of April 22, 1996,
          between the Corporation and Genentech, Inc. (the "Note Agreement")
          shall be an amount per share equal to the Current Market Price (as
          defined below) of the Common Stock determined as of the first
          occurring Conversion Date (as such term is defined in Section 4(a) of
          the Note Agreement) (herein, the "Initial Issue Date"). The
          "Conversion Price" for any shares of Series E Preferred Stock issued
          in connection with a prepayment pursuant to Section


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          3(d) of the Note Agreement shall be an amount per share equal to the
          Current Market Price of the Common Stock determined as of the date of
          the issuance of such shares (herein, the "Prepayment Issue Date"). The
          number of shares of Common Stock into which a share of Series E
          Preferred Stock is convertible is hereinafter referred to as the
          "Conversion Rate" of such series. The Conversion Price shall be
          subject to adjustment from time to time after the Initial Issue Date
          or applicable Prepayment Issue Date, as the case may be, as set forth
          in this Section 6.

               For purposes of this Section 6(A), "Current Market Price" shall
          mean the average daily Closing Prices (as defined below) per share of
          Common Stock for the fifteen (15) consecutive trading days immediately
          prior to the Initial Issue Date or applicable Prepayment Issue Date,
          as the case may be. "Closing Price" with respect to any securities on
          any day shall mean the closing sale price regular way on such day or,
          in case no such sale takes place on such day, the average of the
          reported closing bid and asked prices, regular way, in each case on
          the New York Stock Exchange, or, if such security is not listed or
          admitted to trading on such Exchange, on the principal national
          security exchange or quotation system on which such security is quoted
          or listed or admitted to trading, or, if not quoted or listed or
          admitted to trading on any national securities exchange or quotation
          system, the average of the closing bid and asked prices of such
          security on the over-the-counter market on the day in question as
          reported by the National Quotation Bureau Incorporated, or a similar
          generally accepted reporting service, or, if not so available, in such
          manner as furnished by any New York Stock Exchange member firm
          selected from time to time by the Board of Directors of the
          Corporation for that purpose, or a price determined in good faith by
          the Board of Directors of the Corporation or, to the extent permitted
          by applicable law, a duly authorized committee thereof, whose
          determination shall be conclusive.

               If any shares of Series E Preferred Stock shall be called for
          redemption, the right to convert the shares designated for redemption
          shall terminate at the close of business on the business day next
          preceding the date fixed for redemption unless the Corporation
          defaults in the payment of the redemption price. In the event of a
          default in the payment of the redemption price, the right to convert
          the shares designated for redemption shall terminate at the close of
          business on the business day next preceding the date that such default
          is cured.

               The shares of Common Stock issuable upon conversion of the shares
          of Series E Preferred Stock, when the same shall be issued in
          accordance with the terms hereof, are hereby declared to be and shall
          be fully paid and non-assessable shares of Common Stock in the hands
          of the holders thereof.

               2. Automatic Conversion. Each share of Series E Preferred Stock
          shall automatically be converted into shares of Common Stock at its
          then effective Conversion Rate immediately upon the transfer of
          ownership by the initial holder to any third party which is not an
          Affiliate (as such term is defined below) of such holder. For purposes
          of this Certificate, the term "Affiliate" means, when used with
          respect to any specified person, any other person directly or
          indirectly controlling or controlled by or under direct or indirect
          common control with such specified person. For the purposes of this
          definition, "control," when used with respect to any person, means the
          power to direct the management and policies of such person, directly
          or indirectly, whether through the


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          ownership of voting securities, by contract or otherwise, and the
          terms "affiliated," "controlling" and "controlled" have meanings
          correlative to the foregoing.

               3. Mechanics of Conversion. Each holder of Series E Preferred
          Stock who desires to convert the same into shares of Common Stock
          pursuant to this Section 6 shall surrender the certificate or
          certificates therefor, duly endorsed, at the office of the Corporation
          or any transfer agent for the Series E Preferred Stock, and shall give
          written notice to the Corporation at such office that such holder
          elects to convert the same. Such notice shall state the number of
          shares of Series E Preferred Stock being converted. Thereupon, the
          Corporation shall promptly issue and deliver at such office to such
          holder a certificate or certificates for the number of shares of
          Common Stock to which such holder is entitled and shall promptly pay
          in cash or, to the extent sufficient funds are not then legally
          available therefor, in Common Stock (at the fair market value of the
          Common Stock as of the date of such conversion as determined by the
          Board of Directors of this Corporation), any declared and unpaid
          dividends on the shares of Series E Preferred Stock being converted.
          Such conversion shall be deemed to have been made at the close of
          business on the date of such surrender of the certificates
          representing the shares of Series E Preferred Stock to be converted,
          and the person entitled to receive the shares of Common Stock issuable
          upon such conversion shall be treated for all purposes as the record
          holder of such shares of Common Stock on such date.

               4. Adjustment for Subdivisions and Combinations. If the
          Corporation shall at any time or from time to time after the Initial
          Issue Date or applicable Prepayment Issue Date, as the case may be,
          effect a subdivision of the outstanding Common Stock, the Conversion
          Price in effect immediately before that subdivision shall be
          proportionately decreased. Conversely, if the Corporation shall at any
          time or from time to time after the Initial Issue Date or applicable
          Prepayment Issue Date, as the case may be, combine the outstanding
          shares of Common Stock into a smaller number of shares, the Conversion
          Price in effect immediately before the combination shall be
          proportionately increased. Any adjustment under this Section 6(D)
          shall become effective at the close of business on the date the
          subdivision or combination becomes effective.

               5. Adjustment for Certain Dividends and Distributions. If the
          Corporation at any time or from time to time after the Initial Issue
          Date or applicable Prepayment Issue Date, as the case may be, makes,
          or fixes a record date for the determination of holders of Common
          Stock entitled to receive, a dividend or other distribution payable in
          additional shares of Common Stock, in each such event (without
          duplication for related events) the Conversion Price that is then in
          effect shall be decreased as of the time of such issuance or, in the
          event such record date is fixed, as of the close of business on such
          record date, by multiplying the Conversion Price then in effect by a
          fraction (1) the numerator of which is the total number of shares of
          Common Stock issued and outstanding immediately prior to the time of
          such issuance or the close of business on such record date, and (2)
          the denominator of which is the total number of shares of Common Stock
          issued and outstanding immediately prior to the time of such issuance
          or the close of business on such record date plus the number of shares
          of Common Stock issuable in payment of such dividend or distribution;
          provided, however, that if such record date is fixed and such dividend
          is not fully paid or if such distribution is not fully made on the
          date fixed therefor, the Conversion Price shall be recomputed
          accordingly as of the close of business on such record date and
          thereafter the


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          Conversion Price shall be adjusted pursuant to this Section 6(E) to
          reflect the actual payment of such dividend or distribution.

               6. Adjustment for Other Dividends and Distributions. If the
          Corporation at any time or from time to time after the Initial Issue
          Date or applicable Prepayment Issue Date, as the case may be, makes,
          or fixes a record date for the determination of holders of Common
          Stock entitled to receive, a dividend or other distribution payable in
          securities of the Corporation other than shares of Common Stock, in
          each such event provision shall be made so that the holders of the
          Series E Preferred Stock shall receive upon conversion thereof, in
          addition to the number of shares of Common Stock receivable thereupon,
          the amount of other securities of the Corporation which they would
          have received had their Series E Preferred Stock been converted into
          Common Stock on the date of such event and had they thereafter, during
          the period from the date of such event to and including the conversion
          date, retained such securities receivable by them as aforesaid during
          such period, subject to all other adjustments called for during such
          period under this Section 6 with respect to the rights of the holders
          of the Series E Preferred Stock or with respect to such other
          securities by their terms.

               7. Adjustment for Recapitalizations, etc. If at any time or from
          time to time after the Initial Issue Date or applicable Prepayment
          Issue Date, as the case may be, the Common Stock issuable upon the
          conversion of the Series E Preferred Stock is changed into the same or
          a different number of shares of any class or classes of stock, whether
          by recapitalization, reclassification or otherwise (other than a
          subdivision or combination of shares or stock dividend or a
          reorganization, merger, consolidation or sale of assets provided for
          elsewhere in this Section 6 or in Section 3), in any such event each
          holder of Series E Preferred Stock shall have the right thereafter to
          convert such stock into the kind and amount of stock and other
          securities and property receivable upon such recapitalization,
          reclassification or other change by holders of the maximum number of
          shares of Common Stock into which such shares of Series E Preferred
          Stock could have been converted immediately prior to such
          recapitalization, reclassification or change, all subject to further
          adjustment as provided herein or with respect to such other securities
          or property by the terms thereof.

               8. Compliance with Laws. Notwithstanding any provision of this
          Section 6 to the contrary, no conversion of any share of Series E
          Preferred Stock shall be effective unless such conversion is permitted
          under then applicable laws.

               Section G. Reacquired Shares. Any shares of Series E Preferred
          Stock purchased or otherwise acquired by the Corporation in any manner
          whatsoever shall be retired and canceled promptly after the
          acquisition thereof. All such shares shall upon their cancellation
          become authorized but unissued shares of Preferred Stock and may be
          reissued as part of a new series of Preferred Stock subject to the
          conditions and restrictions on issuance set forth herein, in the
          Amended and Restated Certificate of Incorporation, or in any other
          Certificate of Designation creating a series of Preferred Stock or any
          similar stock or as otherwise required by law.

               Section H. Exclusion of Other Rights.  Except as may otherwise be
          required  by the  General  Corporation  Law of the State of  Delaware,
          shares of the Series E  Preferred Stock shall not have any preferences
          or relative, participating, optional or other


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          special rights, other than those specifically set forth in this
          Certificate of Designation (as such Certificate of Designation may be
          amended from time to time) and in the Corporation's Amended and
          Restated Certificate of Incorporation, as amended. No shares of Series
          E Preferred Stock shall have any preemptive or subscription rights
          whatsoever as to any securities of the Corporation.

               Section I. Notice. All notices and other communications  provided
          for or permitted  to be given to the  Corporation  hereunder  shall be
          made by hand delivery,  next day air courier or certified  first-class
          mail to the Corporation at its principal  executive office  (currently
          located  on the  date of the  adoption  of these  resolutions  at 2910
          Seventh  Street,  Berkeley,   California  94710,  Attention:   General
          Counsel).

               Section J. Transferability; Registration; Rights of Transferees.

               1. Transferability. The Series E Preferred Stock may not be sold,
          assigned, conveyed, transferred, pledged, hypothecated or otherwise
          disposed of other than as set forth in, and in accordance with, that
          certain Common Stock and Convertible Note Purchase Agreement, dated as
          of April 22, 1996, between the Corporation and Genentech, Inc.

               2. Transfer Mechanics; Registration. The Series E Preferred Stock
          certificate representing shares of Series E Preferred Stock to be
          transferred shall be duly endorsed by the transferring holder or by
          his duly authorized attorney or representative, or accompanied by
          proper evidence of succession, assignment or authority to transfer. In
          all cases of a transfer by an attorney, the original power of
          attorney, duly approved, or a copy thereof, duly certified, shall be
          deposited and remain with the Corporation. In case of a transfer by
          executors, administrators, guardians or other legal representatives,
          duly authenticated evidence of their authority shall be produced, and
          may be required to be deposited and to remain with the Corporation in
          its discretion. Upon any registration of a transfer, the Corporation
          shall deliver new Series E Preferred Stock certificates to the persons
          entitled to the shares of Series E Preferred Stock represented
          thereby. The Series E Preferred Stock certificates may be exchanged at
          the option of the holder thereof, when surrendered at the offices of
          the Corporation, for other Series E Preferred Stock certificates of
          different denominations, of like tenor and representing in the
          aggregate a like number of shares of Series E Preferred Stock. Any
          Series E Preferred Stock certificate so surrendered shall be promptly
          canceled by the Corporation and retired. Each Series E Preferred Stock
          certificate issued in exchange as provided above shall be
          substantially in the form of the Series E Preferred Stock certificate
          being exchanged and shall be subject to all of the terms and
          provisions hereof.

               3.  Required  Legend(s).  Each of the  Series E  Preferred  Stock
          certificates  shall  contain the  legend(s)  required by that  certain
          Common Stock and  Convertible  Note  Purchase  Agreement,  dated as of
          April 22, 1996, between the Corporation and Genentech, Inc.

               Section K. Amendments. The Certificate of Designation filed
          pursuant hereto may be amended without notice to or the consent of any
          holder of Series E Preferred Stock to cure any ambiguity, defect or
          inconsistency, provided that such amendment does not adversely affect
          the rights of any holder of Series E Preferred Stock. Any provisions


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          of the Certificate of Designation filed pursuant hereto may be amended
          by the Corporation with the written consent of holders of Series E
          Preferred Stock representing a majority of the outstanding shares of
          Series E Preferred Stock.



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     IN WITNESS WHEREOF, the undersigned have executed this certificate as of
April 22, 1996.


                                             ----------------------------------
                                             Clarence L. Dellio
                                             Senior Vice President, Operations



                                             ----------------------------------
                                             Christopher J. Margolin
                                             Vice President, General Counsel
                                                     and Secretary



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