Document:

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                                                                    EXHIBIT 4.46

                           BOATMEN'S BANCSHARES, INC.

                                       and

                             CHEMICAL BANK, Trustee

                          SECOND SUPPLEMENTAL INDENTURE
                           Dated as of March 18, 1993

                          Subordinated Debt Securities

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                          SECOND SUPPLEMENTAL INDENTURE

     SECOND SUPPLEMENTAL INDENTURE, dated as of March 18, 1993 (the "Second
Supplemental Indenture"), by and between BOATMEN'S BANCSHARES, INC., a Missouri
corporation (the "Company") and CHEMICAL BANK, a New York corporation (as
successor by merger to Manufacturers Hanover Trust Company, a New York
corporation), as trustee (the "Trustee").

                             RECITALS OF THE COMPANY

     The Company has heretofore entered into the Indenture, dated as of October
2, 1989 (the "Indenture") to provide for the issuance of its subordinated debt
securities ("Securities") in one or more series and has appointed the Trustee to
serve as trustee thereunder.

     The Company and the Trustee, by First Supplemental Indenture, dated
September 23, 1992 (the "First Supplemental Indenture"), supplemented the
Indenture to provide for the issuance of Securities in global form.

     Pursuant to Sections 2.01, 6.01 and 10.01(f) of the Indenture, the Company
desires to change certain provisions of the Indenture effective only with
respect to any one or more series of Securities issued subsequent to the date of
this Second Supplemental Indenture which are intended to meet the criteria of 12
C.F.R. ss.250.166 and qualify for treatment as tier 2 capital under the rules
and regulations of the Board of Governors of the Federal Reserve System.

     All things necessary to make Securities issued under the Indenture, as
heretofore and hereby supplemented, the valid obligation of the Company, and to
make the Indenture, as heretofore and hereby supplemented, a valid agreement of
the Company, in accordance with their and its terms, have been done as of the
date hereof.

     NOW, THEREFORE, THIS SECOND SUPPLEMENTAL INDENTURE WITNESSETH:

     In order to comply with the requirements of the Indenture, the Company
covenants and agrees with the Trustee for the equal and proportionate benefit of
the holders of Securities issued on or after the date hereof as follows:

                                   ARTICLE ONE
                       AMENDED AND ADDITIONAL DEFINITIONS

     SECTION 101. The "." at the end of the definition of "Senior Indebtedness"
in Article I of the Indenture is hereby changed to a "," and the following
provision added:

     and, with respect only to Qualifying Securities, shall mean (1) the
     principal of, premium, if any, and interest on all indebtedness for money
     borrowed, whether now outstanding or subsequently incurred; (2) all
     obligations to make payment pursuant to the terms of financial instruments,
     such as (a) securities contracts and foreign currency exchange contracts,
     (b) derivative instruments, such as swap agreements (including interest
     rate and foreign exchange rate swap agreements)cap agreements, floor
     agreements, collar agreements, interest rate agreements,

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     foreign exchange agreements, options, commodity futures contracts and
     commodity options contracts, and (c) similar financial instruments;
     (except, in the case of both (1) and (2) above, any such indebtedness or
     obligation that expressly states that it is not superior to the Notes or
     any other subsequently issued series of subordinated debt that is intended
     to be Qualifying Securities, or ranks pari passu therewith); (3) any
     indebtedness or obligation of others of the kind described in both (1) and
     (2) above for the payment of which the Corporation is responsible or liable
     as guarantor or otherwise; and (4) all deferrals, renewals or extensions of
     such indebtedness or obligations.

     SECTION 102. The following definition is added to the provisions of Article
I of the Indenture, following the definition of "Principal Subsidiary" and
preceding the definition of "Register":

     Qualifying Security:

          The term "Qualifying Security" shall mean a Security of a series
     which is intended to meet the criteria specified in 12 C.F.R.
     ss.250.166 and qualify as supplementary capital elements, tier 2
     capital, in accordance with the provisions of Regulation Y, Appendix
     A, promulgated by the Board of Governors of the Federal Reserve System
     under the Bank Holding Company Act of 1956, as amended.

                                ARTICLE TWO
                    DESIGNATION OF QUALIFYING SECURITIES

     SECTION 201. The word "and" is hereby removed from the end of subparagraph
(11) of Section 2.01 of the Indenture (as amended by the First Supplemental
Indenture), added at the end of subparagraph (12), and the following new
subparagraph (13) is hereby added to Section 2.01:

          (13) whether the Securities of the series shall be issued as
     Qualifying Securities and, if so, any additional terms or conditions
     necessary to meet the qualifications for tier 2 capital in accordance
     with the provisions of Regulation Y, Appendix A, as promulgated by the
     Board of Governors of the Federal Reserve System, as amended,
     supplemented and interpreted at the time of such issuance;

                                  ARTICLE THREE
                   PROVISIONS GOVERNING QUALIFYING SECURITIES

     SECTION 301. The following provision is hereby added to Section 4.07 of the
Indenture:

          Notwithstanding any other provision of this Section 4.07 to the
     contrary, the covenants of this Section 4.07 shall not be for the
     benefit of, or enforceable by, holders of Qualifying Securities of any
     series, nor shall the Trustee be entitled

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     to enforce the covenants of this Section 4.07 for the benefit of
     holders of Qualifying Securities of any series.

     SECTION 302. The following provision is hereby added to Section 6.01 of the
Indenture:

          Notwithstanding any other provision of this Article VI to the
     contrary, with respect to Qualifying Securities of any series, an
     "Event of Default" shall mean and include only those events specified
     in subparagraphs (2), (5) and (6) above; the events specified in
     subparagraphs (1), (3), (4) and (7) being hereby specifically deleted
     as "Events of Default" for all purposes with respect to Qualifying
     Securities. Without limitation on the foregoing, the occurrence of any
     event described in subparagraphs (1), (3), (4) or (7) shall not
     entitle the holders of Qualifying Securities of any series, or the
     Trustee on behalf of any such holders, to accelerate the maturity of
     such Qualifying Securities.

                                  ARTICLE FOUR
           INDENTURE AMENDMENTS WITH RESPECT TO QUALIFYING SECURITIES

     SECTION 401. Section 4.08 of the Indenture is hereby deleted and replaced
by the following:

          "Section 4.08. Waiver of Covenants. The Company may omit in any
     particular instance to comply with any covenant or condition set forth
     in Section 4.07, or any covenant or condition specifically contained
     in this Indenture for the benefit of one or more series of Securities
     (except covenants which cannot be amended without the consent of all
     holders pursuant to Section 10.02 hereof), if before the time for such
     compliance the holders of a majority in principal amount of the
     Securities of all series (with Securities other than Qualifying
     Securities voting as one class and Qualifying Securities voting as a
     separate class) benefiting from the covenant (determined as provided
     in Section 8.04) shall waive such compliance in such instance, but no
     such waiver shall extend to or affect such covenant or condition
     except to the extent so expressly waived, and, until such waiver shall
     become effective, the obligations of the Company and the duties of the
     Trustee in respect of any such covenant or condition shall remain in
     full force and effect."

     SECTION 402. The first paragraph of Section 10.02 of the Indenture is
hereby deleted and replaced by the following:

     "Section 10.02. Modification of Indenture with Consent of Holders of a
     Majority in Principal Amount of Securities. With the consent (evidenced as
     provided in Section 8.01) of the holders of not less than a majority in
     principal amount of the Securities of all series at the time outstanding
     (determined as provided in Section 8.04) affected by such supplemental
     indenture (with Securities other than Qualifying Securities voting as one
     class and Qualifying Securities voting as a separate class), the Company,
     when authorized by a resolution of its Board of Directors, and the Trustee
     may from time to

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       time and at any time enter into an indenture or indentures supplemental
       hereto (which shall comply with the provisions of the Trust Indenture Act
       of 1939 as then in effect) for the purpose of adding any provisions to or
       changing in any manner or eliminating any of the provisions of this
       Indenture or of any supplemental indenture of modifying in any manner the
       rights of the holders of the Securities of each such series; provided,
       however, that no such supplemental indenture shall (i) extend the fixed
       maturity of any Securities, or reduce the rate or extend the time of
       payment of any interest thereon or on any overdue principal amount, or
       reduce the principal amount thereof, or change the provisions pursuant to
       which the rate of interest on any Security is determined if such change
       could reduce the rate of interest thereon, or reduce the minimum rate of
       interest thereon, or reduce any amount payable upon any redemption or
       acceleration thereof, or make the principal thereof or any interest
       thereon or on any overdue principal amount payable in any coin or
       currency other than that provided in the Security, without the consent of
       the holder of each Security so affected, or (ii) reduce the aforesaid
       percentage of Securities, the holders of which are required to consent to
       any such supplemental indenture, without the consent of the holders of
       all Securities then outstanding."

       SECTION 403. The first sentence of Section 12.04 of the Indenture is
hereby deleted and replaced by the following:

              "Section 12.04. Subrogation to Rights of Holders of Senior
       Indebtedness. Subject to the prior payment in full of all Senior
       Indebtedness of the Company, the holders shall be subrogated (with (i)
       Securities other than Qualifying Securities being subrogated equally and
       ratably with the holders of all indebtedness of the Company which by its
       express terms is not superior in right of payment to Securities other
       than Qualifying Securities and ranks pari passu with the Securities other
       than Qualifying Securities and is entitled to like rights of subrogation
       and (ii) Qualifying Securities being subrogated equally and ratably with
       the holders of all indebtedness of the Company which by its express terms
       is not superior in right of payment to the Qualifying Securities and
       ranks pari passu with the Qualifying Securities and is entitled to like
       rights of subrogation) to the rights of the holders of such Senior
       Indebtedness to receive payments or distributions of assets or securities
       of the Company applicable to the Senior Indebtedness of the Company until
       the Securities shall be paid in full."

                                  ARTICLE FIVE
                                  MISCELLANEOUS

       SECTION 501. Except as otherwise expressly provided or unless the context
otherwise requires, all terms used herein which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

       SECTION 502. The recitals contained herein shall be taken as the
statements of the Company only, and the Trustee assumes no responsibility for
their correctness. The Trustee makes no representations as to the validity or
sufficiency of this Second Supplemental Indenture.

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       SECTION 503. This Second Supplemental Indenture shall be governed by and
construed in accordance with the laws of the jurisdiction which govern the
Indenture and its construction.

       SECTION 504. This Second Supplemental Indenture may be executed in any
number of counterparts each of which shall be an original, but such counterparts
shall together constitute but one and the same instrument.

       SECTION 505. In accordance with Section 10.04 of the Indenture, all
Securities authenticated and delivered after the execution of this Second
Supplemental Indenture shall bear the following notation:

              "As of March 18, 1993, the Indenture, dated as of October 2, 1989,
       relating to this Security has been amended by a First Supplemental
       Indenture, dated as of September 23, 1992, and further amended by a
       Second Supplemental Indenture, dated as of March 18, 1993."

       IN WITNESS WHEREOF, the parties hereto have caused this Second
Supplemental Indenture to be duly executed and their respective seals to be
affixed hereunto and duly attested all as of the day and year first above
written.

[SEAL]                             BOATMEN'S BANCSHARES, INC.

ATTEST:

/s/ DAVID L. FOULK                 By  /s/ JAMES W. KIENKER
-----------------------------        ------------------------------------------
Assistant Secretary                  James W. Kienker
                                     Executive Vice President

[SEAL]                             CHEMICAL BANK (as successor by merger to
                                   Manufacturers Hanover Trust Company),
                                   Trustee
ATTEST:

/s/ G. JOHN KISER                  By  /s/ W. D. DODGE
-----------------------------        ------------------------------------------
Trust Officer                        Vice President

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STATE OF MISSOURI         )
                          ) ss.
CITY OF ST. LOUIS         )

       On the 18th day of March, in the year 1993, before me personally came
James W. Kienker, to me known, who, being by me duly sworn, did depose and say
that he resides at 2 Geyerwood Lane, St. Louis, Missouri; that he is the
Executive Vice President of Boatmen's Bancshares, Inc., a corporation described
in and which executed the above instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument is such corporate seal;
that it was so affixed pursuant to the authority of the Board of Directors of
said corporation; and that he signed his name thereto pursuant to like
authority.

                                                 /s/ KAY C. ANDERSON
                                                      Notary Public

STATE OF NEW YORK         )
                          ) ss.
CITY OF NEW YORK          )

       On the 25th day of March, in the year 1993, before me personally came
W.D. Dodge, to me known, who, being by me duly sworn, did depose and say that,
he resides at 3532 Kenora Pl., Seaford, N.Y.; that he is a Vice President of
Chemical Bank, a corporation described in and which executed the above
instrument; that he knows the seal of said corporation; that the seal affixed to
said instrument is such corporate seal; that it was so affixed pursuant to the
authority of the Board of Directors of said corporation; and that he signed his
name thereto pursuant to like authority.

                                                 /s/ ALICIA COSTELLO
                                                      Notary Public

                                       7<PAGE>

                                                                    EXHIBIT 4.47

                             NB HOLDINGS CORPORATION

                                                                      "Holdings"

                             Successor by merger to
                           BOATMEN'S BANCSHARES, INC.

                             NATIONSBANK CORPORATION

                                                                   "NationsBank"

                            THE CHASE MANHATTAN BANK
                                     f/k/a
                                 CHEMICAL BANK,
                             successor by merger to
                       MANUFACTURERS HANOVER TRUST COMPANY

                                                                       "Trustee"

                          THIRD SUPPLEMENTAL INDENTURE

                           Dated as of January 7, 1997

                          Subordinated Debt Securities

<PAGE>

                          THIRD SUPPLEMENTAL INDENTURE

     THIRD SUPPLEMENTAL INDENTURE, dated as of January 7, 1997, by and between
NATIONSBANK CORPORATION, a North Carolina corporation ("NationsBank"), NB
HOLDINGS CORPORATION, a Delaware corporation and wholly-owned subsidiary of
NationsBank ("Holdings"), and THE CHASE MANHATTAN BANK, a New York corporation
formerly known as Chemical Bank, as successor by merger to Manufacturers Hanover
Trust Company (the "Trustee") under the Indenture, dated as of October 2, 1989
(the "Indenture") of BOATMEN'S BANCSHARES, INC., a Missouri corporation
("Boatmen's").

                      RECITALS OF NATIONSBANK AND HOLDINGS

     WHEREAS, Boatmen's has heretofore entered into the Indenture to provide for
the issuance, from time to time, of its subordinated debt securities (the
"Securities") and the Trustee (formerly known as Chemical Bank, a New York
corporation, and successor by merger to Manufacturers Hanover Trust Company, a
New York corporation) was appointed to serve as trustee thereunder;

     WHEREAS, pursuant to an Agreement and Plan of Merger, dated as of August
29, 1996, as amended, by and among Boatmen's, NationsBank and Holdings,
Boatmen's shall be merged into Holdings on or about January 7, 1997 (the
"Effective Time") with Holdings as the surviving corporation, and Holdings shall
succeed to and assume all rights and obligations of Boatmen's as a result
thereof and NationsBank desires to join with Holdings in succeeding to the
rights and obligations of Boatmen's arising under the Indenture;

     WHEREAS, all things necessary to make the Securities issued under the
Indenture, as hereby supplemented, the valid obligations of NationsBank and
Holdings, and to make the Indenture, as hereby supplemented, a valid agreement
of NationsBank and Holdings, in accordance with their and its terms, have been
done as of the Effective Time.

     NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH:

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     In order to comply with the requirements of the Indenture, NationsBank and
Holdings, jointly and severally, covenant and agree with the Trustee for the
equal and proportionate benefit of the holders of the Securities as follows:

                                   ARTICLE ONE
                           ASSUMPTION BY THE SUCCESSOR

     Section 101. NationsBank and Holdings hereby represent and warrant, jointly
and severally, to the Trustee and to the holders of the Securities as follows:

          (a) Immediately after giving effect to the Merger (as hereafter
defined), neither NationsBank nor Holdings shall be in default in the
performance or observance of any of the terms, covenants and conditions of the
Indenture to be kept or performed by NationsBank or Holdings, respectively.

          (b) NationsBank is a corporation organized and existing under the laws
of the State of North Carolina and owns one hundred percent of Holdings, a
Delaware corporation.

          (c) At the Effective Time, Boatmen's shall be merged into Holdings,
said merger being hereinafter referred to as the "Merger".

     Section 102. NationsBank and Holdings hereby jointly and severally assume
the due and punctual payment of the principal of (and premium, if any) and
interest on the Securities, according to their tenor, and the due and punctual
performance and observance of all of the covenants and conditions of the
Indenture to be performed or observed by Boatmen's in accordance with the terms
of the Indenture, as previously and hereby supplemented.

     Section 103. NationsBank and Holdings shall jointly and severally succeed
to, and be substituted for, and may exercise every right and power of, Boatmen's
under the Indenture with the same effect as if NationsBank and Holdings had been
originally named therein.

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                                   ARTICLE TWO
                                  MISCELLANEOUS

     Section 201. Except as otherwise expressly provided or unless the context
otherwise requires, all terms used herein which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

     Section 202. This Supplement shall be effective as of the Effective Time,
being the time of the effectiveness of the Merger.

     Section 203. The recitals contained herein shall be taken as the statements
of NationsBank and Holdings, and the Trustee assumes no responsibility for their
correctness. The Trustee makes no representations as to the validity or
sufficiency of this Supplement.

     Section 204. This Supplement shall be governed by and construed in
accordance with laws of the jurisdiction which govern the Indenture and its
construction.

     Section 205. This Supplement may be executed in any number of counterparts
each of which shall be an original, but such counterparts shall together
constitute but one and the same instrument.

     Section 206. In accordance with Section 10.04 of the Indenture, all
Securities authenticated and delivered after the execution of this Third
Supplemental Indenture shall bear the following notation:

          As of January 7, 1997, the Indenture dated October 2, 1989, relating
          to this Security has been amended by the First Supplemental Indenture,
          dated as of September 23, 1992, a Second Supplemental Indenture, dated
          as of March 18, 1993, and a Third Supplemental Indenture dated as of
          January 7, 1997.

                            [Signature Pages Follow]

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     IN WITNESS WHEREOF, the parties hereto have caused this Supplement to be
duly executed and their respective seals to be affixed hereunto and duly
attested all as of the day and year first above written.

[SEAL]                                     NATIONSBANK CORPORATION

ATTEST:

/s/ James W. Kiser                         By  /s/ John E. Mack
--------------------------------             -----------------------------------
Secretary

[SEAL]                                     NB HOLDINGS CORPORATION

ATTEST:

/s/ James W. Kiser                         By  /s/ John E. Mack
--------------------------------             -----------------------------------
Secretary

[SEAL]                                     THE CHASE MANHATTAN BANK

ATTEST:

/s/ Francine Springer                      By  /s/ Glenn G. McKeever
--------------------------------             -----------------------------------
Authorized Officer

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STATE OF NORTH CAROLINA            )
                                   ) SS.
COUNTY OF MECKLENBURG              )

     On this 30th day of December, 1996, before me personally appeared John E.
Mack, to me personally known, who being duly sworn, did say that he is the
Senior Vice President & Treasurer of NB HOLDINGS CORPORATION, that the seal
affixed to this instrument is the corporate seal of said corporation, and that
the said instrument was signed and sealed on behalf of said corporation by
authority of its Board of Directors and the said John E. Mack acknowledged said
instrument to be the free act and deed of said corporation.

     IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year first above written.

                                     /s/ Melva Hanna
                                     -------------------------------------------
                                     Notary Public

My commission expires:  10-27-2000

STATE OF NORTH CAROLINA            )
                                   ) SS.
COUNTY OF MECKLENBURG              )

     On this 30th day of December, 1996, before me personally appeared John E.
Mack, to me personally known, who being duly sworn, did say that he is the Sr.
Vice President & Treasurer of NATIONSBANK CORPORATION, that the seal affixed to
this instrument is the corporate seal of said corporation, and that the said
instrument was signed and sealed on behalf of said corporation by authority of
its Board of Directors and the said John E. Mack acknowledged said instrument to
be the free act and deed of said corporation.

     IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year first above written.

                                     /s/ Melva Hanna
                                     -------------------------------------------
                                     Notary Public

My commission expires:  10-27-2000

                                       6

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STATE OF __________________ )
                            ) SS.
COUNTY OF ________________  )

     On this 6th day of January, 1997, before me personally appeared GLENN G.
McKEEVER, to me personally known, who being duly sworn, did say that he is the
SENIOR TRUST OFFICER of The Chase Manhattan Bank, that the seal affixed to this
instrument is the corporate seal of said association, and that the said
instrument was signed and sealed on behalf of said association by authority of
its Board of Directors and the said ______________________________ acknowledged
said instrument to be the free act and deed of said corporation.

     IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year first above written.

                                      /s/ Emily Fayan
                                      -----------------------------------
                                      Notary Public

My commission expires:  EMILY FAYAN
                        Notary Public, State of New York
                        No. 24-4737006
                        Qualified in Kings County
                        Certificate filed in New York County
         `              Commission Expires December 31, 1997

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