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：1971
卷号：68
期号：10
页码：2569-2573
DOI：10.1073/pnas.68.10.2569
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Half-cystine peptic peptides representing the intrachain disulfide bonds of the light chain from an apparently homogeneous rabbit anti-p-azobenzoate antibody were isolated in good yields after reduction and alkylation with [14C]iodoacetate, and their sequences were determined. The sequence of the first 21 amino-terminal residues was also determined. The good yields of these peptides, the fact that no variants of any of them were found, and the cleanness of the amino-terminal sequence determination confirm the high degree of homogeneity of this light-chain preparation. Previous evidence for the homogeneity of the light chain includes the appearance of only a single band upon analysis by disc electrophoresis, a relatively unique amino-acid composition, and a simple tryptic peptide map. The whole antibody shows a homogeneity of the hapten-binding constant. The antigen used in the present work is complex, since the attached hapten groups are in a large variety of environments, particularly since the carrier is a heterogeneous mixture of globulins. The very limited heterogeneity of the antibodies found in this case would appear to depend on the stimulation of only a few of the cells capable of producing antibody against a given hapten, rather than on a structural identity of the environment around each individual hapten group that is located on the antigen molecule.
