Structure of the Fab fragment of F105, a broadly reactive anti-human immunodeficiency virus (HIV) antibody that recognizes the CD4 binding site of HIV type 1 gp120.

ABSTRACT: We have determined the crystal structure of the Fab fragment from F105, a broadly reactive human antibody with limited potency that recognizes the CD4 binding site of gp120. The structure reveals an extended CDR H3 loop with a phenylalanine residue at the apex and shows a striking pattern of serine and tyrosine residues. Modeling the interaction between gp120 and F105 suggests that the phenylalanine may recognize the binding pocket of gp120 used by Phe(43) of CD4 and that numerous tyrosine and serine residues form hydrogen bonds with the main chain atoms of gp120. A comparison of the F105 structure to that of immunoglobulin G1 b12, a much more potent and broadly neutralizing antibody with an overlapping epitope, suggests similarities that contribute to the broad recognition of human immuno

SUBMITTER: Wilkinson RA 

PROVIDER: S-EPMC1235812 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature