title: Structural requirements of KTS-disintegrins for inhibition of alpha(1)beta(1) integrin.
abstract: Obtustatin and viperistatin represent the shortest known snake venom monomeric disintegrins. In the present study, we have produced recombinant full-length wild-type and site-directed mutants of obtustatin to assess the role of the K(21)TS(23) tripeptide and C-terminal residues for specific inhibition of the alpha(1)beta(1) integrin. Thr(22) appeared to be the most critical residue for disintegrin activity, whereas substitution of the flanking lysine or serine residues for alanine resulted in a less pronounced decrease in the anti-alpha(1)beta(1) integrin activity of the disintegrin. The triple mutant A(21)AA(23) was devoid of blocking activity towards alpha(1)beta(1) integrin-mediated cell adhesion. The potency of recombinant KTS-disintegrins also depended on the residue C-terminally adjacent to the active motif. Substitution of Leu(24) of wild-type obtustatin for an alanine residue slightly decreased the inhibitory activity of the mutant, whereas an arginine residue in this position enhanced the potency of the mutant over wild-type obtustatin by 6-fold. In addition, the replacements L38V and P40Q may account for a further 25-fold increase in alpha(1)beta(1) inhibitory potency of viperistatin over KTSR-obtustatin.
authors.affiliation: Department of Biology, Center for Neurovirology, Temple University School of Medicine, Phildelphia, PA 19122, USA.
authors.forename: Meghan C
authors.initials: MC
authors.lastname: Brown
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Eble
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Calvete
authors.forename: Cezary
authors.initials: C
authors.lastname: Marcinkiewicz
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D024141:Collagen Type IV / Q000378:metabolism; D003198:Computer Simulation; D019483:Disintegrins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D039222:Integrin alpha1beta1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D012910:Snake Venoms / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014757:Viper Venoms / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology
chemical_list: D024141:Collagen Type IV; D019483:Disintegrins; D039222:Integrin alpha1beta1; D011994:Recombinant Proteins; D012910:Snake Venoms; D014757:Viper Venoms; C474313:obtustatin, Vipera lebetina obtusa