title: Identification of inhibitors of α2β1 integrin, members of C-lectin type proteins, in Echis sochureki venom.
abstract: Snake venom antagonists of α2β1 integrin have been identified as members of a C-lectin type family of proteins (CLP). In the present study, we characterized three new CLPs isolated from Echis sochureki venom, which interact with this integrin. These proteins were purified using a combination of gel filtration, ion exchange chromatography and reverse phase HPLC. Sochicetin-A and sochicetin-B potently inhibited adhesion of cells expressing α2β1 integrin and binding of isolated α2β1 ectodomain to collagen I, as well as bound to recombinant GST-α2A domain in ELISA, whereas activity of sochicetin-C in these assays was approximately two orders of magnitude lower. Structurally, sochicetin-B and sochicetin-C are typical heterodimeric αβ CLPs, whereas sochicetin-A exhibits a trimer of its subunits (αβ)₃ in the quaternary structure. Immobilized sochicetins supported adhesion of glioma cell lines, LN18 and LBC3, whereas in a soluble form they partially inhibited adhesion of these cells to collagen I. Glioma cells spread very poorly on sochicetin-A, showing no cytoskeleton rearrangement typical for adhesion to collagen I or fibronectin. Adhesion on CLP does not involve focal adhesion elements, such as vinculin. Sochicetin-A also inhibited collagen-induced platelet aggregation, similar to other CLPs' action on the blood coagulation system.
authors.affiliation: Department of Biology, Temple University, Philadelphia, PA 19122, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Jakubowski
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Calvete
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Eble
authors.forename: Philip
authors.initials: P
authors.lastname: Lazarovici
authors.forename: Cezary
authors.initials: C
authors.lastname: Marcinkiewicz
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D056148:Chromatography, Reverse-Phase; D024042:Collagen Type I / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005353:Fibronectins / Q000378:metabolism; D005910:Glioma / Q000378:metabolism* / Q000473:pathology; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D038982:Integrin alpha2beta1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D020014:K562 Cells; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014162:Transfection; D014757:Viper Venoms / Q000737:chemistry*
chemical_list: D024042:Collagen Type I; D005353:Fibronectins; D038982:Integrin alpha2beta1; D007527:Isoenzymes; D010975:Platelet Aggregation Inhibitors; D011506:Proteins; D014757:Viper Venoms; D005982:Glutathione Transferase; C119995:glutathione S-transferase alpha