A novel TNFalpha antagonizing peptide-Fc fusion protein designed based on CDRs of TNFalpha neutralizing monoclonal antibody.
The variable regions of antibody molecules bind antigens with high affinity and specificity. The binding sites are imparted largely to the hypervariable portions (i.e., CDRs) of the variable region. Peptides derived from CDRs can bind antigen with similar specificity acting as mimic of antibody and become drug-designing core, although with markedly lower affinity. In order to increase the affinity and bioactivity, in this study, a novel peptide (PT) designed on CDRs of a TNFalpha neutralizing monoclonal antibody Z12 was linked with Fc fragment of human IgG1. The interaction mode of PT-linker-Fc (PLF) with TNFalpha was analyzed with computer-guided molecular modeling method. After expression in Escherichia coli and purification, recombinant PT-linker-Fc could bind directly with the TNFalpha coated on the ELISA plates. Furthermore, PLF could competitively inhibit the binding of Z12 to TNFalpha and also inhibit the TNFalpha-induced cytotoxicity on L929 cells. The TNFalpha antagonizing activity of PLF was significantly higher than that of the free peptide. This study highlights the potential of human Fc to enhance the potency of peptides designed on the CDRs of antibodies and could be useful in developing new TNFalpha antagonists.
Qin
Weisong
W
Institute of Basic Medical Sciences, Beijing, PR China. qinws@nic.bmi.ac.cn
Feng
Jiannan
J
Zhang
Wei
W
Li
Yan
Y
Shen
Beifen
B
D000911:Antibodies, Monoclonal / Q000276:immunology*; D001483:Base Sequence; D001665:Binding Sites; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000138:chemical synthesis* / Q000276:immunology / Q000494:pharmacology; D015183:Restriction Mapping; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha