title: Different regions of the class P-III snake venom metalloproteinase jararhagin are involved in binding to alpha2beta1 integrin and collagen.
abstract: SVMPs are multi-domain proteolytic enzymes in which disintegrin-like and cysteine-rich domains bind to cell receptors, plasma or ECM proteins. We have recently reported that jararhagin, a P-III class SVMP, binds to collagen with high affinity through an epitope located within the Da-disintegrin sub-domain. In this study, we evaluated the binding of jararhagin to alpha(2)beta(1) integrin (collagen receptor) using monoclonal antibodies and recombinant jararhagin fragments. In solid phase assays, binding of jararhagin to alpha(2)beta(1) integrin was detectable from concentrations of 20 nM. Using recombinant fragments of jararhagin, only fragment JC76 (residues 344-421), showed a significant binding to recombinant alpha(2)beta(1) integrin. The anti-jararhagin monoclonal antibody MAJar 3 efficiently neutralised binding of jararhagin to collagen, but not to recombinant alpha(2)beta(1) integrin nor to cell-surface-exposed alpha(2)beta(1) integrin (alpha(2)-K562 transfected cells and platelets). The same antibody neutralised collagen-induced platelet aggregation. Our data suggest that jararhagin binding to collagen and alpha(2)beta(1) integrin occurs by two independent motifs, which are located on disintegrin-like and cysteine-rich domains, respectively. Moreover, toxin binding to collagen appears to be sufficient to inhibit collagen-induced platelet aggregation.
authors.affiliation: Laboratório de Imunopatologia, Instituto Butantan, Butantã, São Paulo, SP, Brazil.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Tanjoni
authors.forename: Karla
authors.initials: K
authors.lastname: Evangelista
authors.forename: Maisa S
authors.initials: MS
authors.lastname: Della-Casa
authors.forename: Diego
authors.initials: D
authors.lastname: Butera
authors.forename: Geraldo S
authors.initials: GS
authors.lastname: Magalhães
authors.forename: Cristiani
authors.initials: C
authors.lastname: Baldo
authors.forename: Patrícia B
authors.initials: PB
authors.lastname: Clissa
authors.forename: Irene
authors.initials: I
authors.lastname: Fernandes
authors.forename: Johannes
authors.initials: J
authors.lastname: Eble
authors.forename: Ana M
authors.initials: AM
authors.lastname: Moura-da-Silva
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects; D003094:Collagen / Q000187:drug effects / Q000378:metabolism*; D003435:Crotalid Venoms / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D038982:Integrin alpha2beta1 / Q000187:drug effects / Q000378:metabolism*; D020014:K562 Cells / Q000187:drug effects / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D014162:Transfection; D000097146:Bothrops jararaca Venom
chemical_list: D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D003094:Collagen; D003435:Crotalid Venoms; D038982:Integrin alpha2beta1; D008666:Metalloendopeptidases; D010975:Platelet Aggregation Inhibitors; D011994:Recombinant Proteins; D000097146:Bothrops jararaca Venom