title: A homogeneous assay system of aspartate aminotransferase iso-enzymes using proteases and application for clinical evaluation of myocardial infarction.
abstract: We designed a rapid, homogeneous assay for human aspartate aminotransferase (AST) isoenzymes, by a selective proteolysis of soluble AST (s-AST), using chymotrypsin and protease 401. The linearity of mitochondrial (m-AST) was elongated up to 4000 U/l. m-AST values from the human liver, and determined by a homogeneous assay using protease 401 or chymotrypsin, were relative to those obtained using an immunoprecipitation method. In perioperative patients or those with an acute myocardial infarction, the peaks of s-AST and m-AST values were noted 13 h and at 57 h after ictus, respectively, whereas the peak of ratio between was seen 6 h after ictus. In the case of Budd-Chiari syndrome, the maximum levels of the two AST activities were evident 14 days after hospitalization and the peak of ratio between them was seen after 7 days. We propose that this homogeneous assay can serve as a diagnostic tool for early phase detection of myocardial infarction and of Budd-Chiari syndrome.
authors.affiliation: Division of Clinical Laboratory, National Cardiovascular Center, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoneda
authors.forename: Y
authors.initials: Y
authors.lastname: Katayama
authors.forename: T
authors.initials: T
authors.lastname: Koike
authors.forename: I
authors.initials: I
authors.lastname: Tanimizu
mesh_terms: D000328:Adult; D000368:Aged; D001219:Aspartate Aminotransferases / Q000032:analysis* / Q000037:antagonists & inhibitors; D015415:Biomarkers / Q000032:analysis; D006502:Budd-Chiari Syndrome / Q000175:diagnosis / Q000201:enzymology; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis* / Q000037:antagonists & inhibitors; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000201:enzymology; D012016:Reference Values; D012697:Serine Endopeptidases
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D001219:Aspartate Aminotransferases; D012697:Serine Endopeptidases