       Document 0350
 DOCN  M9640350
 TI    Interaction between a Fab fragment against gp41 of human
       immunodeficiency virus 1 and its peptide epitope: characterization using
       a peptide epitope library and molecular modeling.
 DT    9604
 AU    Stigler RD; Ruker F; Katinger D; Elliott G; Hohne W; Henklein P; Ho JX;
       Keeling K; Carter DC; Nugel E; et al; Institut fur Medizinische
       Immunologie, Universitatsklinikum; Charite, Humboldt-Universitat zu
       Berlin, Germany.
 SO    Protein Eng. 1995 May;8(5):471-9. Unique Identifier : AIDSLINE
       MED/96016641
 AB    The molecular interaction of the Fab fragment of the human monoclonal
       antibody 3D6, directed against the transmembrane protein gp41 of human
       immunodeficiency virus (HIV) 1, with its peptide epitope is
       characterized by a panel of overlapping peptides, a peptide epitope
       library and molecular modeling techniques. The sequence CSGKLICTTAVPW,
       corresponding to amino acids 605-617 of gp41, was identified as the best
       binding peptide (KD = 1 x 10(-8) mol/l). This peptide served as a
       starting point to prepare a cellulose-bound peptide epitope library in
       which each residue of the epitope is substituted by all L- and D-amino
       acids, resulting in 494 epitope peptide variants which were subsequently
       analyzed for binding 3D6. The library was synthesized to identify
       residues critical for binding and to obtain information about the
       molecular environment of the epitope peptide bound to 3D6. Both cysteine
       residues, as well as isoleucine 6, threonine 8 and proline 12, of the
       epitope were highly sensitive to substitution. Using the data obtained
       from the epitope characterization, as well as a low-resolution electron
       density map of a 3D6 Fab-peptide complex, a 3-D model of the Fab-peptide
       complex was generated by molecular modeling. The modeling experiments
       predict binding of the peptide, which is cyclized via the two cysteine
       residues, to a pocket formed dominantly by the hypervariable loops
       complementarity determining regions CDR3L, CDR2H and CDR3H.
 DE    Amino Acid Sequence  Antibodies, Monoclonal/IMMUNOLOGY  Binding Sites
       Cloning, Molecular  Computer Graphics  Epitopes/CHEMISTRY/METABOLISM
       Human  Hydrogen Bonding  HIV Envelope Protein
       gp41/CHEMISTRY/*IMMUNOLOGY/METABOLISM  HIV-1/CHEMISTRY/*IMMUNOLOGY
       Immunodominant Epitopes  Immunoglobulins,
       Fab/CHEMISTRY/*IMMUNOLOGY/METABOLISM  Models, Molecular  Molecular
       Sequence Data  Peptides/CHEMISTRY/METABOLISM  Protein Conformation
       Recombinant Fusion Proteins/CHEMISTRY/ISOLATION & PURIF/  METABOLISM
       Support, Non-U.S. Gov't  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

