Identification of the plasminogen activator inhibitor-1 binding heptapeptide in vitronectin.
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.
Mimuro
J
J
Institute of Hematology, Jichi Medical School, Tochigi-ken, Japan.
Muramatsu
S
S
Kurano
Y
Y
Uchida
Y
Y
Ikadai
H
H
Watanabe
S
S
Sakata
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D001666:Binding Sites, Antibody; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000032:analysis* / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D019096:Vitronectin
D000911:Antibodies, Monoclonal; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D009842:Oligopeptides; D017395:Plasminogen Activator Inhibitor 1; D019096:Vitronectin