| abstract |
A thrombin-like enzyme isolated from Agkistrodon acutus venom, comprising an alpha subunit having a defined sequence of SEQ ID NO.1 given in the description and a beta subunit having a defined sequence of SEQ ID NO. 2 given in the description, interconnected by seven disulfide linkages, is provided. The enzyme of present invention is a serine proteinase capable of hydrolyzing alpha chain of human fibrinogen, and has a molecular weight of 29.3~29.5kD and an isoelectric point of 5.5. Methods for purifying such enzyme, comprising removing insoluble substance of the venom by pretreatment, conducting twice of anion-exchange chromatography, collecting active eluting peak, dialysing, ultrafiltrating and desalinating, are also provided. The thrombin-like enzyme obtained from said methods has a specific activity of no less then 180u/mg protein, a HPLC purity of more than 95% and a yield of 0.7%-0.8% based on weight of venom raw material. |