The enzyme carbamyl phosphate-ornithine transcarbamylase, which catalyzes the synthesis of citrulline from ornithine plus carbamyl phosphate, has been partially purified from rat liver by means of heat treatment and ethanol fractionation (1). Krebs et al. (2) were able to demonstrate the arsenolysis of citrulline in a number of tissues and, by using sheep liver mitochondria, were able to purify...

Transcarbamylases reversibly transfer a carbamyl group from carbamylphosphate (CP) to an amine. Although aspartate transcarbamylase and ornithine transcarbamylase (OTC) are well characterized, little was known about putrescine transcarbamylase (PTC), the enzyme that generates CP for ATP production in the fermentative catabolism of agmatine. We demonstrate that PTC (from Enterococcus faecalis), ...

Lactobacillus sake isolated from meat can hydrolyze arginine via the arginine deiminase pathway. Two enzymes, arginine deiminase and ornithine transcarbamylase, have been revealed by detection of their reaction products, citrulline and ornithine, respectively. The production of citrulline depends on the concentration of glucose in a synthetic medium; it does not occur when the concentration of ...

ammonia is a toxic material for mammalians. it is detoxificated and converted to urea in the urea cycle in liver. each defect in the urea cycle cause increase in blood ammonia level. ornithine transcarbamylase enzyme (otc) is the second enzyme in the urea cycle that exists in mitochondria. otc deficiency is the most common hereditary disorder in the urea cycle. in this study, 45 hyper ammonia p...

A number of years ago studies with bacteria indicated a role of biotin in the carboxylation reaction forming a 4 carbon unit essential for aspartate biosynthesis (1, 2). These studies led to extensive work on the role of biotin in the incorporation of bicarbonate into various metabolites. A role of biotin in transcarbamylase reactions was demonstrated when biotin-deficient cells of Streptococcu...

INTRODUCTION Unexplained hyperammonemic coma in adults can be a medical dilemma in the absence of triggering factors and known comorbidities. Ornithine transcarbamylase deficiency presents most commonly with hyperammonemic coma. Although a rare disorder, ornithine transcarbamylase deficiency is the most common of the urea cycle disorders, which can occur both in children, and less commonly, in ...

The clinical course and management of a boy with severe ornithine transcarbamylase deficiency are described. In addition to treatment with sodium benzoate and amino acid keto analogues, mannitol may be useful in hyperammonaemia and nocturnal gavage feeding aids maintenance treatment.

The biosynthesis of urea from ammonia and carbon dioxide requires five enzymes. One enzyme, carbamylphosphate synthetase converts ammonia and bicarbonate to carbamyl phosphate, which subsequently condenses with ornithine to form citrulline, a reaction catalysed by ornithine transcarbamylase. Citrulline is then converted by argininosuccinic acid synthetase to argininosuccinic acid, which is clea...