Evidence that type 1 plasminogen activator inhibitor binds to the somatomedin B domain of vitronectin.

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Citation

Seiffert D, Loskutoff DJ

Evidence that type 1 plasminogen activator inhibitor binds to the somatomedin B domain of vitronectin.

J Biol Chem. 1991 Feb 15;266(5):2824-30.

PubMed ID
1704366 [ View in PubMed
]
Abstract

The interaction between type 1 plasminogen activator inhibitor (PAI-1) and fragments of vitronectin (Vn) was investigated. The PAI-1-binding domain was not destroyed when Vn was cleaved by treatment with either acid or CNBr. Acid-cleaved Vn was fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analyzed by PAI-1 ligand binding. The smallest fragment (Mr 40,000) that retained PAI-1 binding function was sequenced and shown to contain the NH2 terminus of the molecule. Further cleavage of this fragment by treatment with CNBr generated a Mr 35,000 fragment (Pro52-Asp239) that did not interact with PAI-1, and a Mr 6,000 NH2-terminal fragment (Asp1-Met51) that spanned the somatomedin B domain and contained the RGD (cell binding) sequence. The purified Mr 6,000 fragment competed with immobilized Vn for PAI-1 binding, and formed complexes with activated PAI-1. These complexes could be immunoprecipitated by antibodies to PAI-1. Synthetic peptides containing the RGD sequence had no effect on the binding of this fragment to PAI-1. These results suggest that the cell-binding and PAI-1 binding sequences of Vn occupy distinct regions in the NH2-terminal somatomedin B domain of the molecule.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
VitronectinP04004Details