Immunochemical studies on phospholipase A2 from Naja nigricollis venom

Document Type : Original Article

Authors

1 Molecular biology department, National research center, Cairo, Egypt

2 Chemistry department, Faculty of Science, Helwan University, Egypt

Abstract

Four PLA2 isoenzymes (N. nigricollis CM-PLA2I-IV) were purified from Naja nigricollis (N. nigricollis) venom using Sephadex G-50 gel filtration, and ion exchange chromatography on CM-Sephadex C-25. The characterization of the isolated PLA2 isoenzymes revealed similarities in molecular weights, and differences in the isoelectric points, the optimum temperature, optimum pH, optimum Ca+2concentration and metal ion requirements. A good correlation (r   <0.7) for the in vitro neutralization of enzymatic PLA2s activity and the ELISA titers was found for sera collected at one week from each boosting of the rabbits. The found correlations were particularly high (r>0.9) when the purified Seph-PLA2 and CM-PLA2II were used rather than the whole venom. The established correlations show the importance of the purified PLA2 enzymes as immunogens for raising therapeutic antisera and as diagnostic reagents for in vitro determination of the potency of the therapeutic antisera.

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