A tentative but almost complete amino acid sequence for the subunit peptide chain of bovine liver glutamate dehydrogenase indicates a minimal size of 506 residues with a molecular weight of 56,100, in accord with the physical size of the subunit of 55,900. Inactivation with pyridoxal 5'-phosphate, followed by reduction with sodium borohydride, has permitted identification of the essential lysin...

We found that the simple addition of L-methionine to the wild type of Corynebacterium glutamicum results in excretion of the cellular building block L-lysine up to rates of 2.5 nmol/min/mg (dry weight). Biochemical analyses revealed that L-methionine represses the homoserine dehydrogenase activity and reduces the intracellular L-threonine level from 7 to less than 2 mM. Since L-lysine synthesis...

The effects of glucagon on the output of amino acids by the isolated rat liver perfused with recirculating medium were to decrease that of glycine, glutamate, and phenylalanine; to increase greatly that of leucine, isoleucine, valine, and tyrosine; and to increase slightly that of lysine and histidine. In livers perfused with nonrecirculating medium containing amino acids at concentrations foun...

The extracellular hemoglobin of Ascaris has an extremely high oxygen affinity (P50 = 0.004 mmHg). It consists of eight identical subunits of molecular weight 40,600. Their sequence, determined by protein chemistry, shows two tandemly linked globin-like sequences and an 18-residue C-terminal extension. Two N-linked glycosylation sites contain equal ratios of mannose/glucosamine/fucose of 3:2:1. ...

BACKGROUND This study aimed to determine amino acid (AA), ammonia and urea concentrations in human ovarian follicular fluid and to compare these concentrations with those in the circulation. METHODS Samples of pre-ovulatory follicular fluid and peripheral venous blood were obtained from 14 IVF patients. High-performance liquid chromatography (HPLC) measurements of 25 AAs were the main outcome...

Arginine synthesis and urea formation via the ornithine cycle occurred in sporophore cap and stipe of Coprinus cinereus. Although urease was found at high activity in mycelium and stipe, it was not detectable in extracts of cap tissue, but arginine biosynthesis was specifically amplified during development of the cap as judged from metabolism of isotopically labelled substrates and increased en...

OBJECTIVE The combination of persistent hyperammonemia and hypoketotic hypoglycemia in infancy presents a diagnostic challenge. Investigation of the possible causes and regulators of the ammonia and glucose disposal may result in a true diagnosis and predict an optimum treatment. PATIENT Since the neonatal period, a white girl had been treated for hyperammonemia and postprandial hypoglycemia ...

Lysine intake during gestation has a major impact on subsequent reproductive performance. The objective of this experiment was to determine the effect of lysine intake from mid-gestation until farrowing on the reproductive performance of multiparous sows. On day 30 of gestation, 200 Landrace×Large White sows were randomly assigned to one of four groups based on body weight and parity (n = 50). ...

Recently, Ghallab and colleagues have identified a novel strategy to reduce hyper-ammonemia in mice (Ghallab et al., 2015). The authors reduced blood ammonia concentrations by infusing a cocktail of glutamate dehydrogenase and its cofactors alpha-ketoglutarate and NADPH. This approach may be clinically relevant, because therapy of hyperammonemia is challenging (Levesque et al., 1999; Enns et al...

The urea cycle converts ammonia, a waste product of protein catabolism, into urea. Because fish dispose ammonia directly into water, the role of the urea cycle in fish remains unknown. Six enzymes, N-acetylglutamate synthase (NAGS), carbamylphosphate synthetase III, ornithine transcarbamylase, argininosuccinate synthase, argininosuccinate lyase and arginase 1, and two membrane transporters, orn...