竹叶青（Trimeresurus　stejnegeri）蛇毒——对5＇－核苷酸酶的分离纯化及理化和酶学性质研究

The Study of Trimersesurus Stejnegeri Snake Venom the Separation and Purification of Its 5 nucleotidase

用ＤＥＡＥ－Ｓｅｐｈａｄｅｘ－Ａ－５０分离竹叶青粗毒，再经ＣＭ－Ｓｅｐｈａｒｏｓｅ－ＣＬ－６Ｂ、ＱＡＥ－Ｓｅｐｈａｄｅｘ－Ａ－５０和ＳｅｐｈａｄｅｘＧ－１００纯化，得到一个５－核苷酸酶，对血小板聚集具有强抑制作用。在ＳＤＳ—聚丙烯酰胺凝胶电泳图谱上为一单一蛋白带，分子量为８２５００，是一个糖蛋白，含６．７％中性糖和０．７％唾液酸。对ＡＭＰ的专一性５－核苷酸酶活力为４３０±４６μｇｐｉ／ｍｉｎｍｇ，ＡＤＰ酶活力为１５３±９μｇｐｉ／ｍｉｎｍｇ。ＥＤＴＡ可抑制它的酶活性，Ｃｏ２＋、Ｃａ２＋离子可部分恢复被ＥＤＴＡ抑制的酶活性。最适ｐＨ范围为８．５～９．５。是一个热稳定糖蛋白。

By DEAE Sephadex A 50,CM Sephadex CL 6B,QAE Sephadex A 50,Sephadex G 100 Seccesively,a 5 nucleotidase was purified from Trimeresurus stejnegeri snake venom.It had a potent inhibitory effect on platelet aggregation.In SDS Polyacrylamide gel electrophoresis,it was a single protein band,its molecule weight was 82 500.It is a glycoprotein,contains 6.7% neutral hexose,0.7% sialic acid. Its specific activities toward AMP and ADP were 430±46 μg Pi/min mg and 153±9 μg Pi/min mg.EDTA could inhibit the 5 nucleotidase activity,Co 2+ ,Cu 2+ could reverse the inhibitory effect.It is a thermostableprotein,its activity was not affected in 60℃ for 30 minutes.