In contrast with putrescine (1,4-diaminobutane), which is a substrate of diamine oxidase, monoacetylputrescine is oxidatively deaminated both in vitro and in vivo by monoamine oxidase. The product of this reaction is N-acetyl-gamma-aminobutyrate. The existence of a degradative pathway in mammalian brain for putrescine is shown, which comprises acetylation of putrescine, oxidative deamination of...

WALSH et a l . 1 recently showed that D-amino acid oxidase is capable of catalyzing a — ß elimination of HCl from D-/?-chloroalanine as well as oxidative deamination. We have also been studying the behavior of this substrate and we wish to briefly point out one aspect of our findings, namely the difficulties we have had in attempting to correlate the steady state turnover behavior of the reacti...

Histamine is formed by decarboxylation of the amino acid L-histidine, a process catalyzed by histidine decarboxylase (HDC) and can be inactivated either by methylation of the imidazole ring, catalyzed by histamine N-methyltransferase (HMT) or by oxidative deamination of the primary amino group, catalyzed by diamine oxidase (DAO). This chapter describes the enzymatic reactions and the properties...

Thermoanaerobacter brockii fermented serine to acetate and ethanol. It oxidized leucine to isovalerate, isoleucine to 2-methylbutyrate, and valine to isobutyrate only in the presence of thiosulfate, or when co-cultured with Methanobacterium sp. This oxidative deamination was rendered thermodynamically possible by the ability ofT. brockii to reduce thiosulfate to sulfide or the transfer of reduc...

Eikenella corrodens 33EK(L), a clinical isolate, was assayed for its ability to utilise amino acids as substrates in the reduction of nitrate to nitrite. The metabolism of proline, glutamate, serine and glutamine was found to result in relatively high rates of nitrate reduction. The ability of cells to metabolise these amino acids from a variety of small peptides was also determined. E. corrode...

Although it has long been thought that environmental toxins may play an underlying role in vascular diseases such as atherosclerosis, this concept is not supported by any clear-cut experimental evidence of toxic metabolism by cardiovascular enzymes. In this study, we demonstrate that allylamine, a selective cardiovascular toxin in vivo, is actively metabolized in vitro by a purified vascular en...

Semicarbazide-sensitive amine oxidase (SSAO) is a copper-containing enzyme that catalyzes the oxidative deamination of endogenous and exogenous primary amines. SSAO exists in mammals both as a plasma-soluble and as a membrane-bound form, and its active site is able to come into contact with numerous xenobiotic, amine-containing compounds. The kinetic studies performed in this work showed that c...

Evidence obtained from experiments with rats and mice is presented suggesting that the naturally occurring amino acids putreanine and N8-(2-carboxyethyl)spermidine, and most probably also related compounds deriving from the polyamines spermidine and spermine by oxidative metabolism, are formed within two anatomical compartments. In the first step polyamines are converted into aldehydes by serum...