Abstract
The cDNA of heterohybridoma mRNA encoding the variable domains of the light (VL) and heavy (VH) chains of an IgG1 bovine monoclonal antibody (MAb) neutralizing bovine herpesvirus 1 was commercially synthesized, cloned and sequenced. The variable (V) light chain sequence had highest identity with members of the V lambda family, 1a subfamily, and the joining (J) gene JL3, both commonly expressed in cattle. The V heavy chain sequence had highest identity with members of the VH1 gene family and JH1, also both commonly expressed in cattle. The VH nucleotide sequence had highest identity with the bovine diversity (D) gene DH3. The derived amino acid sequences were used to examine the complementarity-determining regions (CDRs) according to multiple systems. CDRL1-3 and CDRH1-2 were identified as belonging to or being similar to known canonical classes, and results from “H3 rules” were determined for CDRH3. Models of the Fv structure were derived using three on-line software packages. Overlapping sets of rodent and human MAb were used by the packages as templates for each framework and CDR structure individually. Predictions of the CDRL3 and CDRH3 configurations were more variable than that of other CDRs, and resulted in different paratope models. The results suggest sequences and crystal structures of MAb from a variety of species may be useful in describing additional canonical structures of immunoglobulins.