Ammodytase, a metalloprotease from Vipera ammodytes ammodytes venom, possesses strong fibrinolytic activity

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• 作者：Adrijana Leonardi ; Jay W. Fox ; Alenka Trampu&#x161 ; -Bakija ; Igor Križ ; aj
• 关键词：Snake venom ; Vipera ammodytes ammodytes ; Metalloproteinase ; Fibrinogenase ; Fibrolase ; Antihemorrhagic ; Antithrombotic
• 刊名：Toxicon
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：49
• 期：6
• 页码：833-842
• 全文大小：255 K

文摘

Ammodytase, a high molecular mass metalloproteinase with fibrinogenolytic and fibrinolytic activities, was purified from long-nosed viper (Vipera ammodytes ammodytes) venom by gel filtration, affinity and ion-exchange chromatographies. The enzyme is a single-chain glycoprotein with apparent molecular mass of 70 kDa and isoelectric point of 6.6. Ammodytase shows very weak hemorrhagic activity, and only at doses higher than 20 μg. Consistent with this, it partially degrades some components of the extracellular matrix in vitro. It cleaves the Aα-chain of fibrinogen preferentially at peptide bonds Glu⁴⁴¹–Leu⁴⁴² and Glu⁵³⁹–Phe⁵⁴⁰. Its preference for bulky and hydrophobic amino acids at the P1′ position in substrates is demonstrated by its hydrolysis of only the Gln⁴–His⁵ and Tyr¹⁶–Leu¹⁷ bonds in the B-chain of insulin. Ammodytase is able to dissolve fibrin clots. It neither activates nor degrades plasminogen and prothrombin, and has no effect on collagen- or ADP-induced platelet aggregation in vitro. LC/MS and MS/MS analyses of its tryptic fragments demonstrated that ammodytase is a P-III class snake venom metalloproteinase composed of metalloproteinase, disintegrin-like and cysteine-rich domains. Its similarity to hemorrhagins from V. a. ammodytes venom, accompanied by very low toxicity, makes ammodytase a promising candidate as an antigen to prepare antisera against these most dangerous components of the viper's venom. Moreover, its ability to degrade fibrin clots suggests its clinical use as an antithrombotic agent.