Characterization of an novel chitin binding protein-like venom protein from Pteromalus puparum, an pupal endoparasitoid of Pieris rapae

Chitin binding protein has been studied in many oganisms, like invertebrates, plants and bacterial. Many studies shows it can binding to chitins, carbohydrates and pathogenic bacterias. In this study, we cloned a chitin binding protein-like venom protein(CBPL) from Pteromalus puparum, a pupal parasitoid of pieris rapae. The full length of the cDNA is 448bp and encoded 97aa. The predicted results showed that theoretical isoelectric points of PpCBPL were 4.4, and the related molecular weights were 10.5KD. Its cDNA encoding a typical Peritrophin-A domain. Real time quantitative RT-PCR results verified that the mRNA expression levels of PpCBPL were remarkable high in venom gland. We expressed the recombinant PpCBPL in E.coli. The chitin binding assay shows that the recombinant PpCBPL can binding to chitin beads, but can’t binding to cellulose. The recombinant PpCBPL did not possess the antimicrobial ability for E.coli, Staphylococcus aureus and Pichia pastoris.