1c5y
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STRUCTURAL BASIS FOR SELECTIVITY OF A SMALL MOLECULE, S1-BINDING, SUB-MICROMOLAR INHIBITOR OF UROKINASE TYPE PLASMINOGEN ACTIVATOR
OverviewOverview
BACKGROUND: Urokinase-type plasminogen activator (uPA) is a protease, associated with tumor metastasis and invasion. Inhibitors of uPA may have, potential as drugs for prostate, breast and other cancers. Therapeutically, useful inhibitors must be selective for uPA and not appreciably inhibit, the related, and structurally and functionally similar enzyme, tissue-type, plasminogen activator (tPA), involved in the vital blood-clotting cascade., RESULTS: We produced mutagenically deglycosylated low molecular weight uPA, and determined the crystal structure of its complex with, 4-iodobenzo[b]thiophene 2-carboxamidine (K(i) = 0.21 +/- 0.02 microM). To, probe the structural determinants of the affinity and selectivity of this, inhibitor for uPA we also determined the structures of its trypsin and, thrombin complexes, of apo-trypsin, apo-thrombin and apo-factor Xa, and of, uPA, trypsin and thrombin bound by compounds that are less effective uPA, inhibitors, benzo[b]thiophene-2-carboxamidine, thieno[2,3-b]-pyridine-2-carboxamidine and benzamidine. The K(i) values of, each inhibitor toward uPA, tPA, trypsin, tryptase, thrombin and factor Xa, were determined and compared. One selectivity determinant of the, benzo[b]thiophene-2-carboxamidines for uPA involves a hydrogen bond at the, S1 site to Ogamma(Ser190) that is absent in the Ala190 proteases, tPA, thrombin and factor Xa. Other subtle differences in the architecture of, the S1 site also influence inhibitor affinity and enzyme-bound structure., CONCLUSIONS: Subtle structural differences in the S1 site of uPA compared, with that of related proteases, which result in part from the presence of, a serine residue at position 190, account for the selectivity of small, thiophene-2-carboxamidines for uPA, and afford a framework for, structure-based design of small, potent, selective uPA inhibitors.
DiseaseDisease
Known disease associated with this structure: Alzheimer disease, late-onset, susceptibility to OMIM:[191840]
About this StructureAbout this Structure
1C5Y is a Protein complex structure of sequences from Homo sapiens with FLC and ESP as ligands. Active as U-plasminogen activator, with EC number 3.4.21.73 Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for selectivity of a small molecule, S1-binding, submicromolar inhibitor of urokinase-type plasminogen activator., Katz BA, Mackman R, Luong C, Radika K, Martelli A, Sprengeler PA, Wang J, Chan H, Wong L, Chem Biol. 2000 Apr;7(4):299-312. PMID:10779411
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