Amino acid sequence of the variable domains of a human anti-Rh(c) antibody: presence of an unusually long CDR3 in the lambda chain.

Overview

The complete amino acid sequence of the lambda light chain and the variable domain of the heavy chain of an anti-Rh(c) human monoclonal antibody were determined. The lambda chain presents a long third complementarity-determining region sequence with unusual amino acid insertions at the C-terminus. The proposed sequence indicates that this lambda chain may be assigned to the variable region subgroup I. The J segment is identical to that of J lambda 2 except for the first amino acid residue. Positions 152 (serine) and 190 (arginine) from this sequence correspond to the Kern-Oz- isotype, respectively. The VH segment can be classified as a VHIII subgroup member. The CDR1 segment of the anti-Rh(c) VH region has the same sequence as the VH of human BRO protein except for the first residue of the CDR1. The amino acid sequence of the anti-Rh(c) D segment does not match any published D segment. The JH segment used in this protein can be classified as a JH3 with a single amino acid difference at the fourth residue.