Search results for "Amino Acid Metabolism"

TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2).

2016

In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) su…

Investigation on a MMACHC mutant from cblC disease: The c.394C>T variant

2022

The cblC disease is an inborn disorder of the vitamin B12 (cobalamin, Cbl) metabolism characterized by methylmalonic aciduria and homocystinuria. The clinical consequences of this disease are devastating and, even when early treated with current therapies, the affected children manifest symptoms involving vision, growth, and learning. The illness is caused by mutations in the gene codifying for MMACHC, a 282aa protein that transports and transforms the different Cbl forms. Here we present data on the structural properties of the truncated protein p.R132X resulting from the c.394C > T mutation that, along with c.271dupA and c.331C > T, is among the most common mutations in cblC. Althou…

Regulation of the Urea Cycle during Lactation

1990

We have recently shown that the uptake of amino acids by rat lactating mammary gland is 15 mmoles/day (1). This effect is achieved by an increase in food intake during lactation and probably by changes in amino acid metabolism in other tissues. Rat liver removes 75% of the total amino acids derived from a protein meal (2); therefore plays a key role in the regulation of plasma amino acid concentration.

Lysine triggers apoptosis through a NADPH oxidase-dependent mechanism in human renal tubular cells

2012

Progressive chronic kidney disease (CKD) is common in lysinuric protein intolerance (LPI), a primary inherited aminoaciduria characterized by massive Lysine excretion in urine. However, by which mechanisms Lysine may cause kidney damage to tubule cells is still not understood. This study determined whether Lysine overloading of human proximal tubular cells (HK-2) in culture enhances apoptotic cell loss and its associated mechanisms. Overloading HK-2 with Lysine levels reproducing those observed in urine of patients affected by LPI (10 mM) increased apoptosis (+30%; p < 0.01 vs.C), as well as Bax and Apaf-1 expressions (+30-50% p < 0.05), while downregulated Bcl-2 (-40% p < 0.05). Apoptosis …

Tyrosinaemia type Ia without excess of urinary succinylacetone.

1993

Sarcosinaemia in a retarded, amaurotic child.

1986

A 9-month-old Turkish girl demonstrated an abnormal qualitative amino acid excretion pattern suggestive of sarcosinaemia. She was blind and had evidence of developmental and motor retardation. No other physical abnormalities were noted. Quantitative amino acid analysis revealed elevated serum and urine sarcosine levels. An oral sarcosine loading test showed an exaggerated response with a delayed conversion to glycine. Sarcosine was undetected in other family members.