Localization of a vitronectin binding region of plasminogen activator inhibitor-1.
The PAI-1 binding site for VN was studied using two independent methods. PAI-1 was cleaved by Staph V8 protease, producing 8 fragments, only 2 of which bound to [125I]-VN. These fragments were predicted to overlap between residues 91-130. Since PAI-2 has structural homology to PAI-1, but does not bind to vitronectin, chimeras of PAI-1 and PAI-2 were constructed. Four chimeras, containing PAI-1 residues 1-70, 1-105, 1-114, and 1-167 were constructed and expressed in vitro. PAI-1, PAI-2, and all of the chimeras retained inhibitory activity for t-PA, but only the chimera containing PAI-1 residues 1-167 formed a complex with VN. Together, these results predict that the VN binding site of PAI-1 is between residues 115-130.
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017396:Plasminogen Activator Inhibitor 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D019096:Vitronectin / Q000378:metabolism*
D018076:DNA, Complementary; D010446:Peptide Fragments; D017395:Plasminogen Activator Inhibitor 1; D017396:Plasminogen Activator Inhibitor 2; D011993:Recombinant Fusion Proteins; D019096:Vitronectin; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase