title: The disintegrin-like domain of the snake venom metalloprotease alternagin inhibits alpha2beta1 integrin-mediated cell adhesion.
abstract: The alpha2beta1 integrin is a major collagen receptor that plays an essential role in the adhesion of normal and tumor cells to the extracellular matrix. Here we describe the isolation of a novel metalloproteinase/disintegrin, which is a potent inhibitor of the collagen binding to alpha2beta1 integrin. This 55-kDa protein (alternagin) and its disintegrin domain (alternagin-C) were isolated from Bothrops alternatus snake venom. Amino acid sequencing of alternagin-C revealed the disintegrin structure. Alternagin and alternagin-C inhibit collagen I-mediated adhesion of K562-alpha2beta1-transfected cells. The IC50 was 134 and 100 nM for alternagin and alternagin-C, respectively. Neither protein interfered with the adhesion of cells expressing alphaIIbeta3, alpha1beta1, alpha5beta1, alpha4beta1 alphavbeta3, and alpha9beta1 integrins to other ligands such as fibrinogen, fibronectin, and collagen IV. Alternagin and alternagin-C also mediated the adhesion of the K562-alpha2beta1-transfected cells. Our results show that the disintegrin-like domain of alternagin is responsible for its ability to inhibit collagen binding to alpha2beta1 integrin.
authors.affiliation: Department of Ciências Fisiológicas Universidade Federal de São Carlos, SP, Brazil.
authors.forename: D H
authors.initials: DH
authors.lastname: Souza
authors.forename: M R
authors.initials: MR
authors.lastname: Iemma
authors.forename: L L
authors.initials: LL
authors.lastname: Ferreira
authors.forename: J P
authors.initials: JP
authors.lastname: Faria
authors.forename: M L
authors.initials: ML
authors.lastname: Oliva
authors.forename: R B
authors.initials: RB
authors.lastname: Zingali
authors.forename: S
authors.initials: S
authors.lastname: Niewiarowski
authors.forename: H S
authors.initials: HS
authors.lastname: Selistre-de-Araujo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017837:Bothrops; D016466:CHO Cells; D002448:Cell Adhesion / Q000187:drug effects*; D003094:Collagen / Q000378:metabolism; D006224:Cricetinae; D003435:Crotalid Venoms / Q000201:enzymology* / Q000494:pharmacology*; D019483:Disintegrins / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D016023:Integrins / Q000037:antagonists & inhibitors* / Q000235:genetics; D020014:K562 Cells; D008666:Metalloendopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D038981:Receptors, Collagen; D017386:Sequence Homology, Amino Acid; D014162:Transfection
chemical_list: D003435:Crotalid Venoms; D019483:Disintegrins; D016023:Integrins; D038981:Receptors, Collagen; D003094:Collagen; D008666:Metalloendopeptidases