桂北五步蛇纤溶酶金属蛋白酶原基因的初步研究

从桂北五步蛇毒腺中抽提蛇毒总 RNA,采用一步法 (RT- PCR和 PCR在同一试管内进行 )扩增纤溶酶金属蛋白酶原基因 ,并进行电泳检测 ,可见 3条特异的 DNA条带 ,分别约为 1.5 Kb、 1.3Kb和 80 0 bp,利用平端连接的方法将其中的 80 0 bp PCR产物克隆至 p GEM- T Easy载体 ,挑选白色菌落 ,用酶切和 PCR法对其进行鉴定。

桂北五步蛇纤溶酶金属蛋白酶基因的克隆和序列分析

目的 :克隆桂北五步蛇纤溶酶金属蛋白酶基因 ,并对其进行序列分析。方法 :从桂北五步蛇毒腺中抽提总 RNA,采用一步法 (RT- PCR和 PCR在同一管内进行 )扩增出纤溶酶金属蛋白酶基因 ,利用平端连接的方法将 PCR扩增产物克隆至p GEM- T Easy载体 ,挑选白色菌落 ,用酶切和 PCR法对其进行鉴定 ,直接利用纯化 PCR产物进行测序或提取阳性菌落进行测序。结果 :RT- PCR和 PCR扩增得到一 6 0 0 bp产物 ,并被克隆及测序。结论 :该实验产物和已报道的皖南五步蛇纤溶酶金属蛋白酶氨基酸序列相比较 ,有 90 .6 %的同源性 ,这为进一步研究该产物的表达 ,以及表达产物的活性提供条件。

Purification and Characterization of Jerdonitin, a Non-hemorrhagic Metalloproteinase from Trimeresurus jerdonii Venom

Previously, we have purified Jerdonitin from Trimeresurusjerdonii venom. Compared with other P-Ⅱ class snake venom metalloproteinases （SVMPs）, Jerdonitin has a primary structure comprising metalloproteinase and disintegrin domains. However, no hemorrhagic and fibrinogenolytic activities were detected for Jerdonitin. We thought that organic buffer of high performance liquid charamatography （HPLC） might affect its enzymatic activity. In this study, we purified Jerdonitin by another procedure excluding the HPLC. It was homogenous as judged by SDS-PAGE and had an apparent molecular weight of 36 kDa under non-reducing conditions and 38 kDa under reducing conditions, respectively. Like other typical metalloproteinases, Jerdonitin preferentially degraded alpha-chain of human fibrinogen and this fibrinogenolytic activity was completely inhibited by EDTA, but not by PMSF. It was interesting that Jerdonitin did not induce hemorrhage after intradermal injection in mice.