1
                                                                     Exhibit 4.1


                                   APPENDIX A



                CERTIFICATE OF INCORPORATION OF ANERGEN DELAWARE


   2
                          CERTIFICATE OF INCORPORATION

                                       OF

                                  ANERGEN, INC.


                                    ARTICLE I

        The name of this corporation is Anergen, Inc. (the "Corporation").

                                   ARTICLE II

        The address of the Corporation's registered office in the State of
Delaware is Corporation Trust Center, 1209 Orange Street, in the City of
Wilmington, County of New Castle, zip code 19801. The name of its registered
agent at such address is The Corporation Trust Company.

                                   ARTICLE III

        The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware.

                                   ARTICLE IV

        The Corporation is authorized to issue two classes of stock to be
designated respectively Common Stock and Preferred Stock. The total number of
shares of all classes of stock which the Corporation has authority to issue is
Seventy Million (70,000,000), consisting of Sixty Million (60,000,000) shares of
Common Stock, $0.001 par value (the "Common Stock"), and Ten Million
(10,000,000) shares of Preferred Stock, $0.001 par value (the "Preferred
Stock").

        The shares of Preferred Stock may be issued from time to time in one or
more series pursuant to a resolution or resolutions providing for such issue
duly adopted by the Board of Directors. The Board of Directors of the
Corporation is expressly authorized, by filing a certificate pursuant to the
applicable law of the State of Delaware, to: (i) establish from time to time the
number of shares to be included in each such series; (ii) fix the rights,
preferences, restrictions and designations of the shares of each such series,
including but not limited to the fixing or alteration of the dividend rights,
dividend rate, conversion rights, conversion rate, voting rights, rights and
terms of redemption (including sinking fund provisions), redemption price or
prices, voting rights and liquidation preferences of any series of Preferred
Stock for which no shares have been issued and are outstanding; (iii) increase
the number of shares of any series at any time; and (iv) decrease the number of
shares of any series prior or subsequent to the issue of shares of that series,
but not below the number of shares of such series then outstanding. In case the
number of shares of any series shall




                                       -1-

   3



be so decreased, the shares constituting such decrease shall resume the status
which they had prior to the adoption of the resolution originally fixing the
number of shares of such series.

                                    ARTICLE V

        The name and mailing address of the incorporator are as follows:

        Anna Itoi
        Wilson Sonsini Goodrich & Rosati
        650 Page Mill Road
        Palo Alto, CA 94304-1050

                                   ARTICLE VI

        The Corporation is to have perpetual existence.

                                   ARTICLE VII

        The election of directors need not be by written ballot unless a
stockholder demands election by written ballot at a meeting of stockholders and
before voting begins or unless the Bylaws of the Corporation shall so provide.

                                  ARTICLE VIII

        The number of directors which constitute the whole Board of Directors of
the Corporation shall be designated in the Bylaws of the Corporation.

                                   ARTICLE IX

        In furtherance and not in limitation of the powers conferred by the laws
of the State of Delaware, the Board of Directors is expressly authorized to
adopt, alter, amend or repeal the Bylaws of the Corporation.

                                    ARTICLE X

        To the fullest extent permitted by the Delaware General Corporation Law
as the same exists or may hereafter be amended, no director of the Corporation
shall be personally liable to the Corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director.

        Neither any amendment nor repeal of this Article, nor the adoption of
any provision of this Certificate of Incorporation inconsistent with this
Article, shall eliminate or reduce the effect of this Article in respect of any
matter occurring, or any cause of action, suit or claim that, but for this
Article, would accrue or arise, prior to such amendment, repeal or adoption of
an inconsistent provision.




                                       -2-

   4


                                   ARTICLE XI

        At the election of directors of the Corporation, each holder of stock of
any class or series shall be entitled to one vote for each share held. No
stockholder will be permitted to cumulate votes at any election of directors.

                                   ARTICLE XII

        Meetings of stockholders may be held within or without the State of
Delaware, as the Bylaws may provide. The books of the Corporation may be kept
(subject to any provision contained in the laws of the State of Delaware)
outside of the State of Delaware at such place or places as may be designated
from time to time by the Board of Directors or in the Bylaws of the Corporation.

                                  ARTICLE XIII

        The Corporation reserves the right to amend, alter, change or repeal any
provision contained in this Certificate of Incorporation, in the manner now or
hereafter prescribed by the laws of the State of Delaware, and all rights
conferred herein are granted subject to this reservation.

        The undersigned incorporator hereby acknowledges that the foregoing
Certificate of Incorporation is her act and deed and that the facts stated
herein are true.

Dated: May 1, 1998


                                                 /s/ Anna Itoi
                                                 ------------------------------
                                                 Anna Itoi



                                       -3-