title: Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases.
abstract: Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.
authors: Laboratório de Imunopatologia, Instituto Butantan, Av. Vital Brasil, São Paulo, SP, Brazil. anamoura@butantan.gov.br
authors: A M
authors: AM
authors: Moura-da-Silva
authors: O H P
authors: OH
authors: Ramos
authors: C
authors: C
authors: Baldo
authors: S
authors: S
authors: Niland
authors: U
authors: U
authors: Hansen
authors: J S
authors: JS
authors: Ventura
authors: S
authors: S
authors: Furlan
authors: D
authors: D
authors: Butera
authors: M S
authors: MS
authors: Della-Casa
authors: I
authors: I
authors: Tanjoni
authors: P B
authors: PB
authors: Clissa
authors: I
authors: I
authors: Fernandes
authors: A M
authors: AM
authors: Chudzinski-Tavassi
authors: J A
authors: JA
authors: Eble
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003094:Collagen / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D003435:Crotalid Venoms / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000378:metabolism; D000097146:Bothrops jararaca Venom
chemical_list: D003094:Collagen; D003435:Crotalid Venoms; D008666:Metalloendopeptidases; D010975:Platelet Aggregation Inhibitors; D000097146:Bothrops jararaca Venom; C504090:berythractivase, Bothrops erythromelas; C069317:hemorrhagic metalloproteinase