Functional expression and characterization of a recombinant phospholipase A2 from sea snake Lapemis hardwickii as a soluble protein in E. coli

Wen Li Yang, Li Sheng Peng, Xiao Fen Zhong, Jian Wen Wei, Xiao Yu Jiang, Lan Ting Ye, Lan Zou, Hong Bin Tu, Wen Yan Wu, An Long Xu

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Three full-length phospholipase A2 (PLA2) cDNAs from sea snake Lapemis hardwickii venom were cloned and sequenced in our previous study. In order to investigate their biological functions, we established a fusion expression system for PLA2-9 in E. coli. The open reading frame encoding mature peptide of PLA2-9 was subcloned into the vector pTRX. The Trx-PLA2-9 fusion protein was expressed as a soluble protein by IPTG induction at 23°C. The fusion protein was purified with metal-chelate affinity chromatography and then cleaved by enterokinase. The mature recombinant PLA2-9 was further purified by ion-exchange chromatography and a final yield of approximately 2.5mg pure PLA2-9 from 1l of bacteria culture was obtained. The catalytic activity of recombinant PLA2-9 (rPLA2-9) was measured and found to be similar to native enzyme. As the Austrelaps superbus PLA2, which shares 90% nucleotide sequence similarity to PLA2-9, the rPLA2-9 displayed the anti-platelet aggregation effect. Site-directed mutagenesis of the two conserved residues, His-48 and Asp-49, resulted in the loss of catalytic activity, however did not affect the inhibition effect of platelet aggregation suggesting that these two activities of sea snake PLA2-9 may be dissociated.

Original languageEnglish (US)
Pages (from-to)713-721
Number of pages9
JournalToxicon
Volume41
Issue number6
DOIs
StatePublished - May 1 2003
Externally publishedYes

Keywords

  • Anti-platelet aggregation effect
  • Phospholipase A
  • Recombinant expression
  • Sea snake Lapemis hardwickii
  • Site-directed mutagenesis

ASJC Scopus subject areas

  • Toxicology

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