W.R. Tulip

TL;DR: There is a small repertoire of main-chain conformations for at least five of the six hypervariable regions of antibodies, and that the particular conformation adopted is determined by a few key conserved residues.

TL;DR: The crystal structure of the complex between neuraminidase from influenza virus and the antigen-binding fragment (Fab) of monoclonal antibody NC41 has been refined by both least-squares and simulated annealing methods to an R-factor of 0.191, suggesting a possible mechanism for the observed inhibition of enzyme activity by the antibody.

TL;DR: Structural studies of cross-reacting antibodies of this type demonstrate the capacity of two different proteins to bind to the same target structure on a third protein need not be based on the existence of identical or homologous amino acid sequences within those proteins.

TL;DR: The crystal structure of the N9 subtype neuraminidase of influenza virus was refined by simulated annealing and conventional techniques to an R-factor of 0.172 for data in the resolution range 6.0 to 2.2 A.s.

TL;DR: The results provide a basis for understanding some of the potential structural effects of somatic hypermutation on antigen-antibody binding in those cases where the mutation in the antibody occurs at antigen-contacting residues, and demonstrate the importance of structural context in evaluating the effect of amino acid substitutions on protein structure and function.