Purification and characterization of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China

Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China.Methods:The arginine ester hydrolase(AEH) was isolated from the venom of Chinese Trimeresurus mucrosqumatus by a combination of ion-exchange chromatography on DEAE-Sephadex A-50, CM-Sepharose Cl-6B and gel filtration on Sephadex G-100.Results: The purified protein named TM-AEH,a glycoprotein with carbohydrate content of 0.5% neutral hexose and 0.75% sialic acid,a relative molecular mass of 29.0 kDa,and an isoelectric point(pI) of 5.2. It shares with an extinction coefficient(E 0.1%/cm) of 1.332 at 280 nm,consisted of 225 amino acid residues,and migrated as a band under reduced or non-reduced condition in basic PAGE.TM-AEH was a highly thermostable protein and was stable to pH changes between 5 and 9.The optimum temperature and optimum pH were 55℃ and 8.4 for its catalytic activity respectively,which was inhibited by Fe 3+ and Cu 2+.Conclusion:This protein can exhibit higher BAEE-hydrolysing activity and fibrinogenolytic activity as compared to that of whole venom.