Portal de Periódicos da CAPES

Bovine brain ketimine reductase

1988; Elsevier BV; Volume: 957; Issue: 2 Linguagem: Inglês

10.1016/0167-4838(88)90285-3

1878-1454

Mirella Nardini, Giorgio Ricci, Loredana Vesci, Laura Pecci, D. Cavallinì,

Biochemical and Molecular Research

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 Δ1-piperidine 2-car☐ylate, 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-dicar☐ylic 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.