
Reactions of cysteamine and other amine metabolites with glyoxylate and oxygen catalyzed by mammalian D-amino acid oxidase.
Author(s) -
Gordon A. Hamilton,
David J. Buckthal,
Richard M. Mortensen,
K W Zerby
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.6.2625
Subject(s) - chemistry , glyoxylate cycle , cysteamine , amino acid , cadaverine , d amino acid oxidase , amine gas treating , biochemistry , spermidine , putrescine , oxidase test , stereochemistry , enzyme , organic chemistry
Pig kidney D-amino acid oxidase [D-amino-acid:oxygen oxidoreductase (deaminating), EC 1.4.3.3] catalyzes a rapid uptake of oxygen when high concentrations (50-100 mM) of glyoxylate and the following amines are present under usual assay conditions (pH 8.3): cysteamine, 2-aminoethanol, putrescine, D,L-1-amino-2-propanol, D,L-2-amino-1-propanol, 3-amino-1-propanol, D,L-octopamine, ethylenediamine, and L-cysteine ethyl ester. Notable physiological amines that do not support a rapid O2 reaction under the above conditions include histamine, serotonin, epinephrine, norepinephrine, spermidine, spermine, and cadaverine. A more detailed kinetic investigation of the reactions involving the first four reactive amines listed above indicated that the cysteamine reaction proceeds at a rapid rate even when cysteamine and glyoxylate are present at less than millimolar concentrations, but greater than millimolar concentrations are needed in the other amine reactions in order to observe a reasonable rate. At low concentrations and pH 7.4, the cysteamine-glyoxylate substrate (presumably thiazolidine-2-carboxylic acid) reacts an order of magnitude faster than any other known D-amino acid oxidase substrate. Considerable circumstantial evidence suggests that the reaction involving cysteamine is occurring physiologically, but the reactions of other amines would be occurring in the cell at a very low rate, if at all. It is proposed that the product of the enzymic reaction may be a metabolic effector that can modify the reactivity of proteins or nucleic acids by covalent attachment.