title: Optimal conditions for protease use in the assay of serum mitochondrial aspartate aminotransferase.
abstract: The optimal conditions for selective proteolytic inactivation of cytosolic aspartate aminotransferase (c-AST) to determine mitochondrial aspartate aminotransferase (m-AST) in serum were studied. Protease 401 was found to be effective over a pH range of 6.0-10.0. A pH of 9.5 with 0.5% albumin in the reagent mixture was determined to be optimal for inactivation of c-AST and preservation of m-AST, lactic dehydrogenase (LDH), and malic dehydrogenase (MDH) in the assay procedure. The presence of serum endogenous protein inhibitors such as alpha 1-antitrypsin and alpha 2-macroglobin did not inhibit protease 401.
authors.affiliation: Department of Laboratory Medicine, Kumamoto University Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okabe
authors.forename: Y
authors.initials: Y
authors.lastname: Uji
authors.forename: H
authors.initials: H
authors.lastname: Sugiuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Watazu
authors.forename: Y
authors.initials: Y
authors.lastname: Shirahase
authors.forename: N
authors.initials: N
authors.lastname: Kaneda
mesh_terms: D001219:Aspartate Aminotransferases / Q000032:analysis* / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology*; D010450:Endopeptidases / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000032:analysis* / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000032:analysis* / Q000378:metabolism; D008930:Mitochondria, Liver / Q000201:enzymology* / Q000378:metabolism; D013381:Subtilisins / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D001219:Aspartate Aminotransferases; D010450:Endopeptidases; D013381:Subtilisins; D002918:Chymotrypsin