Molecular signature analysis of heavy chain CDR residues in human antiª²gp120 antibodies

    FENG Yuan, XING Jinª²Liang, LI Yu, CHEN Zhiª²Nan

    Cell Engineering Research Centre, School of Basic Medicine, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To analyze heavy chain complementarity determinative region (CDR) sequences of human antiª²gp120 antibodies against different epitopes in gp120 and to investigate the relationships between the family utilization, contributions of heavy chain CDR residues, average pI value and their structures and functions. METHODS: A database of Ig heavy chains of antiª²gp120 antibodies was constructed by gleaning data from public databases. Compared with the human antibodies in Kabat database, the family usage and the residues usage, and the average pI value of each epitope group were calculated. Threeª²dimensional structures were modeled with SWISSª²MODEL to verify the results. RESULTS: Compared with the usage of VH1 in normal people (22%), the usage of VH1 in antiª²gp120 antibodies was significantly higher (49%). Significant differences among each epitope group were mainly in CDR2 region, particularly in the region between CD4i group and V3 group. CONCLUSION: Antiª²gp 120 antibody¡¯s tertiary structures and functions are determined by their primary sequences and it has different sequences compared with those of normal antibodies. The difference of sequences may provide some clue in improving the antigen specificity and affinity by reshaping the antiª²gp 120 antibody. ......