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：1974
卷号：71
期号：5
页码：1940-1944
DOI：10.1073/pnas.71.5.1940
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Various enzymatic derivatives of the murine myeloma protein IgAMOPC-315 were subjected to hapten-binding quantitation and circular dichroic analysis in an attempt to ascertain the structural localization and functional definition of the immunoglobulin active site. The extrinsic Cotton effects observed with near saturation of the active site of the derivatives using {varepsilon}-Dnp-L-lysine were qualitatively and quantitatively identical when normalized with respect to their macromolecular content of Dnp-binding sites; ellipticity maxima of 378 and 438 nm and an ellipticity minimum of 325 nm were recorded. Fluorescence quenching data confirmed the molecular nature of the derivation products of IgAMOPC-315 but also introduced disparity with respect to binding kinetics, i.e., K values of 2.31 x 106, 6.62 x 106, and 2.06 x 107 M-1 were determined for IgAMOPC-315, Fab'MOPC-315, and FvMOPC-315, respectively. We speculate that the results can be explained by possible modulating effects on haptenbinding contributed by novel conformations introduced through proteolysis.
