Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases.
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.
Moura-da-Silva
A M
AM
Laboratório de Imunopatologia, Instituto Butantan, Av. Vital Brasil, São Paulo, SP, Brazil. anamoura@butantan.gov.br
Ramos
O H P
OH
Baldo
C
C
Niland
S
S
Hansen
U
U
Ventura
J S
JS
Furlan
S
S
Butera
D
D
Della-Casa
M S
MS
Tanjoni
I
I
Clissa
P B
PB
Fernandes
I
I
Chudzinski-Tavassi
A M
AM
Eble
J A
JA
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
D003094:Collagen; D003435:Crotalid Venoms; D008666:Metalloendopeptidases; D010975:Platelet Aggregation Inhibitors; D000097146:Bothrops jararaca Venom; C504090:berythractivase, Bothrops erythromelas; C069317:hemorrhagic metalloproteinase