ABSTRACT
Objective: To acquire recombinant nematode anticoagulant peptide ( NAP) with high anticoagulant activity. Methods: Pichia pastoris GS115 strain was transformed with recombinant yeast expression vector pPICS. 5K-rNAP. Expression of rNAP was induced with methanol after the identification of positive strains. NAP expressed in the collected yeast culture supernatant was confirmed with SDS-PAGE and Western blot. The biological activity of the products was validated with PT (prothrombin time) , INR (international normalized ratio) and APTT (activated partial thromboplastin time) , respectively. Results: The yeast strains expressing NAP were identified. The rNAP was secreted into culture supernatant with a molecular weight of about 10 kDa due to glycosylation, which is a little bigger than that predicted (8.7kDa). The anticoagulant efficiency of rNAP was confirmed with the in vitro assays. Conclusion: The recombinant nematode anticoagulant peptide with high biological activity was successfully expressed in Pichia pastoris and can be used in the future development of novel anticoagulant agent.