Anticoagulant activities of goby muscle protein hydrolysates

► Anticoagulant activities of protein hydrolysates prepared from goby muscle were investigated. ► The hydrolysate generated by the crude enzyme from Bacillus licheniformis NH1 displayed the highest anticoagulant activity. ► This hydrolysate was then fractionated by size exclusion chromatography on a Sephadex G-25 column into five major fractions. ► Four novel anticoagulant peptides, Leu-Cys-Arg, His-Cys-Phe, Cys-Leu-Cys-Arg and Leu-Cys-Arg-Arg, were identified. The anticoagulant activities of protein hydrolysates prepared from goby muscle by treatment with various bacterial alkaline proteases were investigated. All proteases exhibited varying degrees of hydrolysis (DH) and all goby protein hydrolysates (GPHs) caused a significant prolongation of both the thrombin time (TT) and the activated partial thromboplastin time (APTT). The hydrolysate generated by the crude protease from Bacillus licheniformis NH1 displayed the highest anticoagulant activity, and the higher TT (about 32s) at a concentration of 5mg/mL was obtained with hydrolysate having a DH of 8.86%. This hydrolysate was then fractionated by size exclusion chromatography on a Sephadex G-25 column into five major fractions (F1–F5). Fraction F2, which exhibited the highest anticoagulant activity, was then fractionated by reversed-phase high-performance liquid chromatography. The molecular masses and amino acid sequences of four peptides in peptide sub-fraction F2–6, which exhibited the highest anticoagulant activity, were determined using ESI-MS and ESI-MS/MS, respectively. The structures of these peptides were identified as Leu-Cys-Arg, His-Cys-Phe, Cys-Leu-Cys-Arg and Leu-Cys-Arg-Arg.