Identification of the plasminogen activator inhibitor-1 binding heptapeptide in vitronectin

• Published in: Biochemistry (Easton) Vol. 32; no. 9; pp. 2314 - 2320
• Main Authors: Mimuro, Jun, Muramatsu, Shinichi, Kurano, Yoshihiro, Uchida, Yoshiaki, Ikadai, Hiroyuki, Watanabe, Shunichi, Sakata, Yoichi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09.03.1993
• Subjects: Amino Acid Sequence; Animals; Antibodies, Monoclonal; binding; Binding Sites; Binding Sites, Antibody; Biological and medical sciences; Extracellular Matrix Proteins - chemistry; fibrinolysis; Fundamental and applied biological sciences. Psychology; Glycoproteins - chemistry; Glycoproteins - metabolism; heptapeptide; Humans; identification; Interactions. Associations; Intermolecular phenomena; man; Mice; Molecular biophysics; Molecular Sequence Data; Oligopeptides - analysis; Oligopeptides - metabolism; plasminogen activator inhibitor 1; Plasminogen Activator Inhibitor 1 - metabolism; Rabbits; Sequence Homology, Amino Acid; Vitronectin; Human; Binding protein; Sequence specificity; Enzyme; Peptide fragment; Enzyme inhibitor; Molecular interaction; Plasminogen activator; Vitronectin; Binding site; Blood plasma
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi00060a024

We have shown that a heptapeptide which resides in the middle part of vitronectin (VN) is responsible for binding to plasminogen activator inhibitor-1 (PAI-1). A single PAI-1 binding peptide was isolated from human VN after limited proteolysis with protease V8. The amino acid sequence of the fragment corresponded to residues Gly-115-Glu-121 of VN. A murine monoclonal antibody (JYV-1) raised against human VN bond to the same fragment and inhibited binding of PAI-1 to VN. A synthetic peptide (V-115), comprising residues Gly-115-Glu-121 of human VN, competed with VN for both PAI-1 and JYV-1 in a dose-dependent manner. Synthetic peptide V-111 (Ser-111-Glu-121) had a stronger inhibitory effect than V-115 on binding of PAI-1 or JYV-1 to VN. V-111 also inhibited the binding of human PAI-1 to mouse and rabbit VN. The functional half-life of PAI-1 activity was prolonged approximately 2-fold in the presence of V-111 (1 mM). This stabilizing effect of V-111 was equivalent to intact VN, although a 1000-fold higher molar concentration of V-111 over VN was required. These data indicated that VN residues Gly-115-Glu-121 contain a PAI-1 binding site.