Structure and Themodynamics of Antigen Recognition by Antibodies

BRADEN, BRADFORD C; CAUERHFF, ANA; DALL' ACQUA WILLIAM; FIELDS BARRY A.; GOLDBAUM FERNANDO A.; MALCHIODI EMILIO; MARIUZZA ROY A.; POLJAK ROBERTO J.; SCHWARZ FREDERICK P; YSERN XAVIER; BHAT T.N.

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES.

BLACKWELL PUBLISHING

Lugar: Oxford; Año: 1995 vol. 764 p. 315 - 327

0077-8923

The molecular basis of antigen recognition by antibodies has been approached by X-ray diffraction study of crystalline complexes between protein antigens and Fab or Fv fragments. The antigens in these complexes were hen egg-white lysozyme (HEL), pheasant lysozyme, the influenza virus neuraminidase, the anti-HEL FabD1.3, a phosphocarrier protein from Escherichia coli, and the Fab 730.1.4. These studies showed that antigenic determinants consists of discontinuous sequence segments of the antigeen, bringing about 15 amino acids residues in contact with a similar number of antibody residues, mostly from the complementarity-determining-region (CDRs). Surfaces with areas ranging from about 1300 Å2 to 1900 Å2 are buried upon complex formation in these complexes. The antigen and the antibody may undergo small conformational changes upon complex formation. Chemical contacts between them include a variable number of hydrogen bonds, extensive van der Waals interactions, and, in some complexes, a few ion pairs. In agreement with the fact that CDRs of antibodies contain many arginines and aromatic residues, a large proportion of the contacts with antigens are made by these residues.