期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1992
卷号：89
期号：20
页码：9429-9433
DOI：10.1073/pnas.89.20.9429
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The three-dimensional structure of FabR19.9 from a well-characterized anti-p-azobenzenearsonate monoclonal antibody has been determined by x-ray diffraction techniques in two crystalline forms (I and II) to a resolution of 2.8 and 2.7 A, respectively. Essentially the same tertiary and quaternary structure of the Fab is observed in the two forms. The major difference resides in the intermolecular contacts, which are interpreted to favor an irreversible transition from the metastable form I to the more stable form II. The third complementarity-determining region of the heavy chain (H3) folds back over the combining site and requires rearrangement for hapten binding. This dynamic requirement on H3 is consistent with its mobility in the structure and can explain hapten binding to an otherwise inaccessible antibody combining site.
