title: Comparison of the amino acid sequences of the variable regions of light chains derived from two homogeneous rabbit anti-pneumococcal antibodies.
abstract: The amino acid sequence of the N-terminal 139 residues of the L (light) chain derived from a homogeneous rabbit antibody to type III pneumococci was determined. This L chain, designated BS-5, exhibits a greater degree of homology with the basic sequence of human kappa chains of subgroup I (72%) than with subgroups II and III. L-chain BS-5 differs from another L chain (BS-1), also derived from an antibody to type III pneumococci (Jaton, 1974), by eight amino acid residues, even though the chains are identical within the N-terminal 30 residues. Six of these eight substitutions are located within the three hypervariable sections of the variable half: Asn/Ser in position 31, Glu/Ala in position 55, Asx/Thr, Thr/Gly, Thr/Gly and Val/Tyr in positions 92, 94, 96 and 97 respectively. The two anti-pneumococcal L chains BS-1 and BS-5 are much more similar to each other than to an anti-azobenzoate L chain (Appella et al., 1973), from which they differ by 30 and 29 residues respectively. Of these interchanges 13-15 are confined to the three hypervariable sections, and 11 occur within the N-terminal 27 positions. The three chains have an identical sequence from residue 98 to residue 139, except for a possible inversion of two residues in positions 130-131 of the anti-azobenzoate chain.
mesh_terms: D000156:Aconitic Acid; D000409:Alanine / Q000032:analysis; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D001216:Asparagine / Q000032:analysis; D001224:Aspartic Acid / Q000032:analysis; D001322:Autoanalysis; D002850:Chromatography, Gel; D004590:Electrophoresis, Paper; D005971:Glutamates / Q000032:analysis; D005998:Glycine / Q000032:analysis; D006868:Hydrolysis; D007128:Immunoglobulin Fragments / Q000032:analysis*; D011817:Rabbits / Q000276:immunology; D012694:Serine / Q000032:analysis; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013912:Threonine / Q000032:analysis; D014443:Tyrosine / Q000032:analysis; D014633:Valine / Q000032:analysis
chemical_list: D000596:Amino Acids; D000907:Antibodies, Bacterial; D005971:Glutamates; D007128:Immunoglobulin Fragments; D013912:Threonine; D001224:Aspartic Acid; D014443:Tyrosine; D012694:Serine; D001216:Asparagine; D000156:Aconitic Acid; D014633:Valine; D000409:Alanine; D005998:Glycine