Diversity of PLA(2) Genes from Sea Snake Lapemis hardwickii Gray Venom.

Three full-length cDNA from Lapemis hardwickii Gray, (namely PLA(2)-8, PLA(2)-9 and PLA(2)-384), encoding phospholipase A(2) (PLA(2)), were isolated and sequenced. These cDNA sequences were composed of 456 bp, 438 bp and 438 bp, encoding a signal peptide of 27 amino acids and a mature peptide of 125, 119 and 119 amino acids, respectively. The analysis results by computer indicated PLA(2)-8, PLA(2)-9and PLA(2)-384 has a pI of ca. 4.8, 7.8 and 8.4, respectively. Sequence analysis of amino acid and prediction of secondary structure suggested that these isoforms of PLA(2) belong to class I PLA(2) family. PLA(2)-8 was highly homologous (81%) to Notechis scutatus scutatus (Australian tiger snake) PLA(2), PLA(2)-9 and PLA(2)-384 showed fairly high sequence homology (90%) to Enhydrina schistosa (beaked sea snake) PLA(2), indicating that they might have similar functions. These results reflect the diversity of Lapemis hardwickii Gray PLA(2) genes. The successful cloning of these isoenzyme genes of sea snake PLA(2) may provide new information for the study on structure-function relationship of PLA(2) family and its possible molecular mechanism.