Interaction of snake venom metalloproteinases with type IV collagen: role of the different domains in target biding

Abstract

Snake venom metalloproteinases (SVMPs) disrupt capillary vessels leading to local and systemic hemorrhage. It has been proposed that type IV collagen degradation is one of the key steps in SVMPs-induced hemor- rhage, since hydrolysis of this protein results in a significant weakening of the mechanical stability of the capillary wall. However, the sequences in SVMPs (‘exosites’) which enable them to specifically interact with type IV collagen have not been identified, although it is hypothesized that they are located in the disintegrin-like and cysteine-rich domains characteristic of multi-domain SVMPs. In this study, the interactions of several SVMPs with type IV collagen were investigated in vitro by western blot, ELISA and af- finity chromatography. Hemorrhagic PI, PII and PIII SVMPs, in addition to the DC domain, were compared in the different assays in the presence or absence of a metalloproteinase inhibitor. In all the assays, the strongest binding was observed with CsH1, a PIII SVMP, whereas the PI SVMP BaP1 exhibited the lowest binding, and the PII SVMP BlatH1 presented a mod- erate binding. Interestingly, the binding of the isolated DC domain of CsH1 was lower than the native CsH1 suggesting a role of the metalloproteinase domain in the interaction with type IV collagen.