Inhibitory properties of the anti-bothropic complex from Didelphis albiventris serum on toxic and pharmacological actions of metalloproteases and myotoxins from Bothrops asper venom

Anti-bothropic complex (ABC) was isolated from the serum of the South Ameri can opossum (Didelphis albiventris) by single-step affinity chromatography using a Sepharose-immobilized metalloprotease (BaP1) from Bothrops asper as the binding protein. Biochemical characterization of ABC showed the presen ce of two glycosylated subunits of 43 and 45 kDa, respectively, with an iso electric point < 4. The two subunits were separated by ion-exchange HPLC. T he N-terminal sequences of both subunits (LKAMDPTPXLWIETESP, where X is Arg -9 and Pro-9, respectively) showed a high degree of identity with other ser um inhibitors isolated from different marsupials. Functional studies pointe d out that ABC inhibits the hemorrhagic and proteolytic activities on fibri n, fibrinogen, and casein induced by the metalloproteases BalP1 and BaH4 is olated from B. asper venom. In addition to the anti-hemorrhagic and anti-pr oteolytic activities, ABC also showed anti-myotoxic, anti-lethal, and anti- edematogenic effects against myotoxic phospholipases A(2) isolated from the same venom. Moreover, it had inhibitory effects on the phospholipase A(2) activity of the crude venom as well as the isolated venom phospholipases A( 2) (C) 2001 Elsevier Science Inc. All rights reserved.