کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2065061 | 1076903 | 2010 | 11 صفحه PDF | دانلود رایگان |
The complement system is a very important part of the immune system. Many snake venoms possess activities that influence the complement. A new metalloproteinase (termed atrase B) with anticomplementary activity was purified from Naja atra venom. Atrase B is a single chain glycoprotein with a molecular mass of 49.4 kDa and an isoelectric point of 9.7. Its N-terminal sequence shows high homology to those of metalloproteinases from cobra venoms. The cDNA sequence reveals that atrase B is a PIII class metalloproteinase. Atrase B slowly cleaves the Aα chain of fibrinogen. It also exhibits edema-inducing activity, but has no hemorrhagic activity and proteolytic activity against fibrin, azocasein, and N-benzoyl-l-arginine ethyl ester. Interestingly, atrase B inhibits activation of the complement classical and alternative pathways in a dose- and time-dependent manner. Complement components factor B and C6 are major targets for atrase B to cleave. Atrase B is the first identified SVMP that cleaves complement components factor B, C6, C7, and C8.
Journal: Toxicon - Volume 56, Issue 8, December 2010, Pages 1459–1469