title: Bovine brain ketimine reductase.
abstract: We report the purification from bovine brain of an NAD(P)H-dependent reductase which actively reduces a new class of cyclic unsaturated compounds, named ketimines. Ketimines arise from the transamination of some sulphur-containing amino acids, such as L-cystathionine, S-aminoethyl-L-cysteine and L-lanthionine. The enzyme also reduces delta 1-piperidine 2-carboxylate, the carbon analog of aminoethylcysteine ketimine. Some kinetic and molecular properties of this enzyme have been determined. Subcellular localization and regional brain distribution have also been studied. The ketimine reductase activity was found to be associated with the soluble fraction, and was located prevalently in the cerebellum and cerebral cortices. Cyclothionine and 1,4-thiomorpholine-3,5-dicarboxylic acid, the enzymatic reduction products of cystathionine ketimine and lanthionine ketimine, respectively, have been detected in bovine brain, thus suggesting a role of this enzyme in their biosynthesis.
authors.affiliation: Department of Biochemical Sciences, University of Rome, La Sapienza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Nardini
authors.forename: G
authors.initials: G
authors.lastname: Ricci
authors.forename: L
authors.initials: L
authors.lastname: Vesci
authors.forename: L
authors.initials: L
authors.lastname: Pecci
authors.forename: D
authors.initials: D
authors.lastname: Cavallini
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D001931:Brain Mapping; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000302:isolation & purification* / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; C056073:ketimine reductase