title: [Aldehyde-dehydrogenase from human liver: Purification, partial characterization and influence of malondialdehyde].
abstract: A procedure to separate the isozymes E1 and E2 of aldehyde dehydrogenase (ALDH, aldehyde: NAD oxidoreductase, EC 1.2.1.3) from human liver, avoiding 5'-AMP-Sepharose, was worked out. It results in fairly purified isozymes. The isoelectric points could be re-estimated for E1 at pH 5.21 +/- 0.04 and for E2 at pH 4.90 +/- 0.05. The pH-optimum of both the isozymes is dependent on the buffer used, the best buffer being sodium pyrophosphate/HCI. In this buffer the enzyme activity is also dependent on ionic strength. Malondialdehyde (MDA), at concentrations which are found in patient serum, is converted by the ALDH. The Km-values of this reaction are 1.71 mmol/l for MDA and 0.19 mmol/l for NAD (E1) and 0.21 mmol/l for MDA and 0.24 mmol/l for NAD (E2) resp. The highest rates of conversion are reached at concentrations of 0.08 mmol/l MDA (E1) and 0.16 mmol/l MDA (E2). At higher concentrations of MDA substrate excess inhibition is observed (Kss = 0.17 mmol/l for E1 and 0.20 mmol/l for E2).
authors.affiliation: Klinik und Poliklinik für Innere Medizen, Martin-Luther-Universität Halle-Wittenberg.
authors.forename: H
authors.initials: H
authors.lastname: Wache
authors.forename: I
authors.initials: I
authors.lastname: Böhme
authors.forename: H
authors.initials: H
authors.lastname: Sorger
authors.forename: R
authors.initials: R
authors.lastname: Nilius
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000737:chemistry* / Q000302:isolation & purification; D002845:Chromatography; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008315:Malondialdehyde / Q000494:pharmacology*; D013379:Substrate Specificity
chemical_list: D007527:Isoenzymes; D008315:Malondialdehyde; D000444:Aldehyde Dehydrogenase
vernacular_title: Aldehyddehydrogenase aus Humanleber: Isolierung, partielle Charakterisierung und Einfluss von Malondialdehyd.