The V-region sequence of the H chain from a third rabbit anti-pneumococcal antibody

Publisher Website
Google Scholar
Abstract
The amino acid sequence of the V(variable) region of the H chain (VH) of rabbit antibody BS-1, raised against type III pneumococcal vaccine, is reported. Together with the sequence data of the V region of the L chain previously determined, the present work completes the analysis of the V domain of the homogeneous antibody, BS-1. The V domains (VL + VH regions) of this antibody are compared with those of 2 other anti-(type III) pneumococcal antibodies, BS-5 and K-25. Except for the 2nd hypervariable section of the L chains, these antibodies have very different sequences in the hypervariable segments of the V domains. Within the 2rd hypervariable region of the H chain, each antibody has a different length; BS-1 is 3 amino acids shorter than K-25 and 2 amino acids shorter than BS-5. When the sequences in that section are aligned for maximal homology, only 2 residues, glycine-97 and leucine-101, are common to the 3 antibodies. On the basis of the amino acid sequences of these 3 anti-pneumococcal antibodies, there probably is not a simple correlation between primary structure in the hypervariable sections (known to determine the shape of the combining site) and antigen-binding specificity.