title: Three-stage chromogenic assay for the analysis of activation properties of factor X by cancer procoagulant.
abstract: The cysteine proteinase, cancer procoagulant (CP; EC 3.4.22.26) was isolated from human amnion-chorion and purified by precipitation with polyethylene glycol and either ion exchange or immunoaffinity chromatography. A new, sensitive, three-stage chromogenic assay was developed for determination of CP factor X-activating activity. Using this assay some properties including dose-response, effect of calcium, phospholipid and pH on the activation of factor X by CP was determined. There was an excellent linear correlation (r2 = 0.99) between concentration and the enzymatic activity of CP. The activation of factor X by purified CP was calcium dependent with an optimum calcium concentration of 7 mM. CP was not phospholipid dependent. There was a rather broad pH optimum between pH 6.9 and 7.25 for the activation of factor X by CP.
authors.affiliation: University of Colorado Health Science Center, Denver 80262.
authors.forename: W P
authors.initials: WP
authors.lastname: Mielicki
authors.forename: S G
authors.initials: SG
authors.lastname: Gordon
mesh_terms: D001780:Blood Coagulation Tests; D002118:Calcium / Q000494:pharmacology; D002863:Chromogenic Compounds / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D015951:Factor Xa / Q000096:biosynthesis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009363:Neoplasm Proteins; D009842:Oligopeptides / Q000378:metabolism*; D010743:Phospholipids / Q000494:pharmacology
chemical_list: D002863:Chromogenic Compounds; D009363:Neoplasm Proteins; D009842:Oligopeptides; D010743:Phospholipids; C015608:benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide; D015951:Factor Xa; D003546:Cysteine Endopeptidases; C030910:cancer procoagulant; D002118:Calcium