A novel choline oxidase found in a fungus, Fusarium oxysporum strain V2, was purified to homogeneity as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme has a molecular mass of 128 kDa and consists of two identical subunits. The purified enzyme showed adsorption peaks at 340 nm and 450 nm. It showed alkaliphilic pH characteristics: its optimum pH was 9.0-10.0,...

Debaryomyces vanrijiae MH201 produces formate oxidase (FOD) at estimated pI values by native isoelectric focusing of 5.1, 5.4, and 5.9. We cloned and expressed three formate oxidase cDNAs, FOD1, FOD2, and FDO3, of the yeast using Escherichia coli. The open reading frames of FOD1, FOD2, and FDO3 were 1,731 bp long, and encoded 576-amino acid polypeptides with molecular masses of 64,142, 63,794, ...

The morphine-induced changes in the activity of enzymes involved in the metabolism of neurotransmitters in specific areas of the brain of rats made tolerant to morphine have been investigated. The activities of choline acetyl transferase (E.G.2.3.1.6.), acetylcholinesterase (E.C.3.1.1.7.) and monoamine oxidase (E.G. 1.4.3.4.) were determined in the hippocampus, thalamus, hypothalamus, cerebral ...

An enzymatic method, previously used to determine choline-containing phospholipids in serum, was applied to the estimation of phospholipid concentration in bile. The method combines three enzymatic reactions: a) release of choline by phospholipase D; b) choline oxidation by choline oxidase, a reaction which generates hydrogen peroxide; and c) formation of a red quinone dye by peroxidase. The me...

The formation of the methyl groups of methionine and choline from C”-labeled formate has been demonstrated in the intact rat (1-3) and in rat liver slices (1). Du Vigneaud and his coworkers (’2) have also shown the incorporation of the carbon of formaldehyde into the methyl groups of choline. It is conceivable that in rat liver the carbon of formate or formaldehyde is first incorporated into th...

Choline oxidase catalyzes the flavin-dependent, two-step oxidation of choline to glycine betaine via the formation of an aldehyde intermediate. The oxidation of choline includes two reductive half-reactions followed by oxidative half-reactions. In the first oxidation reaction, the alcohol substrate is activated to its alkoxide via proton abstraction and oxidized via transfer of a hydride from t...

The capacity of the high-affinity choline transporter (CHT) to import choline into presynaptic terminals is essential for acetylcholine synthesis. Ceramic-based microelectrodes, coated at recording sites with choline oxidase to detect extracellular choline concentration changes, were attached to multibarrel glass micropipettes and implanted into the rat frontoparietal cortex. Pressure ejections...