A comprehensive method to explore inhibitory kinetics and mechanisms of an anticoagulant peptide derived from Crassostrea gigas

A comprehensive method was applied to evaluate the anticoagulant activity of a novel anticoagulant peptide (NAESLRK) derived from oyster (Crassostrea gigas). The anticoagulant peptide drastically reduced the extrinsic clotting activity and also impaired the intrinsic clotting activity slightly. Consistent with clotting data, the thrombin peak height was reduced to 84.7 nmol/L from 123.4 nmol/L, and thrombin generation time was delayed to 4.67 min from 4.42 min when the extrinsic trigger was applied. The inhibitory kinetics of FXIa, FIXa, FXa, FIIa, and APC in a purified component system rationally explained the reduction of extrinsic clotting activity and impairment of thrombin generation. Besides the inhibition of FXa and FIIa activity, the activation processes of FX and FII by intrinsic/extrinsic tenase complex and prothrombinase were also damaged. The anticoagulant activity in the plasma system was the result of comprehensive inhibition of various factors. The research provided a novel method for anticoagulant evaluation and inhibitory mechanism of bioactive peptides from food products.