Amino-acid sequences of light chains of a rabbit anti-p-azobenzoate antibody.
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 [(14)C]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.
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D001322:Autoanalysis; D001345:Autoradiography; D001391:Azo Compounds; D001565:Benzoates; D002247:Carbon Isotopes; D002850:Chromatography, Gel; D003553:Cystine / Q000032:analysis; D004586:Electrophoresis; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis; D051379:Mice; D010455:Peptides / Q000032:analysis; D011817:Rabbits
D000906:Antibodies; D001391:Azo Compounds; D001565:Benzoates; D002247:Carbon Isotopes; D007106:Immune Sera; D007136:Immunoglobulins; D010455:Peptides; D003553:Cystine