Purification and Characterization of 5′-nucleotidase from Trimeresurus albolabris Venom

A 5′-nucleotidase was isolated and purified from the snake venom of T. albolabris using three steps of chromatography including DEAE-SephadexA-25, Sephadex-G-100 and CM-Sephadex C-50. Using SDS-PAGE and HPLC column chromatography the purified 5′-nucleotidase proved to be homogenous. It was a glycoprotein with a molecular weight of 48.03 kDa. The enzymatic activities of the purified 5′-nucleotidase were 330.33 µg Pi/min mg and 123.56 µg Pi/min mg when using AMP（adenosine monophosphate） and ADP（adenosine diphosphate） as substrates, respectively. Metal ions, including Zn²⁺, Fe³⁺ and Cu²⁺, could inhibit 5′-nucleotidase activity, as did EDTA. Its optimum pH was nine and its optimum temperature was 50°C. It has a potent inhibitory effect on rabbit platelet aggregation induced by ADP.