Search results for "CYSTEINE"

Blood sulfur-amino acid concentration reflects an impairment of liver transsulfuration pathway in patients with acute abdominal inflammatory processes

2001

Whole-blood free amino acids were measured in a control group made up of eight healthy women fasted for 12 h and also in eight patients with acute pancreatitis, five patients with acute cholecystitis and seven patients with acute appendicitis. Blood was withdrawn immediately on admission to hospital and again 3 d later following a controlled peripheral parenteral nutrition diet; this is with the exception of the appendicitis group. L-CYSTATHIONINE AND l-methionine concentrations were significantly higher in pancreatitis and appendicitis patients when compared with controls. In the pancreatitis and cholecystitis patients, l-serine concentration was also significantly higher when compared wit…

Homocysteine levels in patients with primary and secondary Raynaud's phenomenon. Its association with microangiopathy severity

2013

The association between hyperhomocysteinemia (HHcy) and Raynaud's phenomenon (RP) remains a matter of debate. In 18 primary RP, 23 secondary RP and 41 controls, we investigated homocysteine (Hcy) levels along with biochemical and inflammatory parameters. The Hcy levels in both primary and secondary RP were elevated when compared with controls (p0.05 and p0.01, respectively). As age was higher in secondary RP as compared with controls (p0.01), both primary and secondary RP were age-matched with a corresponding control group, and with Hcy maintaining its statistical significance (p0.05). No differences in creatinine, B12 vitamin or folic acid were observed between groups (p0.05), or in the pr…

Mixed methods analysis of Health-Related Quality of Life in ambulant individuals affected with RYR1-related myopathies pre-post-N-acetylcysteine ther…

2020

Purpose: To characterize Health-Related Quality of Life (HRQoL) in ambulant individuals with RYR1-RM and to determine if a qualitative PRO tool (subjective self-assessment) complements PROMIS and Neuro-QoL scales to detect changes in HRQoL in ambulant individuals with RYR1-RM post N-acetylcysteine (NAC) treatment. Methods: The study used a mixed methods research (MMR) design applying methodological triangulation. Qualitative data were collected via semi-structured interviews using open-ended questions. Quantitative data were gathered through PROMIS and Neuro-QoL instruments. Additionally, qualitative data were transformed into quantitative data for subjective self-assessment and frequency a…

Respiratory chain cysteine and methionine usage indicate a causal role for thiyl radicals in aging

2011

The identification of longevity-related structural adaptations in biological macromolecules may yield relevant insights into the molecular mechanisms of aging. In screening fully sequenced animal proteomes for signals associated with longevity, it was found that cysteine depletion in respiratory chain complexes was the by far strongest predictor on the amino acid usage level to co-vary with lifespan. This association was though restricted to aerobic animals, whereas anaerobic animals showed variable cysteine accumulation. By contrast, methionine accumulation, a prominent feature of mitochondrially encoded proteins affording competitive antioxidant protection, was not predictive of longevity…

The adverse redox biochemistry of intramembrane thiols accounts for the lifespan-dependent cysteine depletion in the inner mitochondrial membrane of …

2013

Differential cysteine depletion in respiratory chain complexes enables the distinction of longevity from aerobicity.

2010

Mitochondrially encoded proteins in long-lived animals exhibit a characteristic anomaly on the amino acid usage level: they abstain from the use of cysteine in a lifespan-dependent fashion. Here, we have further investigated this phenomenon by analyzing respiratory chain complex subunits individually. We find that complex I cysteine depletion is the almost exclusive carrier of the cysteine-lifespan correlation, whereas complex IV cysteine depletion is uniform in all aerobic animals, unrelated to longevity, but even more pronounced than complex I cysteine depletion in the longest-lived species. In nuclear encoded subunits of the respiratory chain, we find lifespan-independent cysteine deplet…

Physiological changes in glutathione metabolism in foetal and newborn rat liver

1991

Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…

Nuevos factores de riesgo cardiometabólico en niños con obesidad severa: influencia del estado puberal

2010

The aim of this prospective study was to evaluate the utility of new biochemical markers to assess cardiometabolic risk in severely obese children and adolescents. A total of 107 subjects aged 7 to 14 years, were clinically assessed and anthropometric measures and percentage of fat mass by single frequency bioimpedance analysis were recorded. Of these, 44 were non-overweight and 63 severely obese (body mass index Z-score >2.5) which were stratified by Tanner stages. To estimate the metabolic risk the following variables were considered for analysis: Waist circumference/height >0.5, fasting glucose >100 mg/dL, triglycerides >110 mg/dL, HDL-C 95th percentile for age and gender. Fasting insuli…

Alkylation at the active site of the D-3-hydroxybutyrate dehydrogenase (BDH), a membrane phospholipid-dependent enzyme, by 3-chloroacetyl pyridine ad…

1997

The structure of the rat liver's D-3-hydroxybutyrate dehydrogenase (BDH) active site has been investigated using an affinity alkylating reagent, the 3-chloroacetyl pyridine adenine dinucleotide (3-CAPAD). This NAD+ analogue reagent strongly inactivates the enzyme following a concentration- and time-dependent process with a stoichiometry of approximately 1. The reagent reacts at the coenzyme binding site as revealed by the efficient protection by NADH. The effect of 3-CAPAD is stronger with the enzyme into its natural membrane environment than with the lipid-free purified apoBDH or with the reconstituted apoBDH-mitochondrial phospholipid complex. The pH-dependent effect on the inactivation p…

Paramagnetic NMR investigations of Co(II) and Ni(II) amicyanin.

1999

The paramagnetic 1H NMR spectra of the Co(II) and Ni(II) substituted forms of the type 1 blue copper protein (cupredoxin) amicyanin have been assigned. This is the first such analysis of a cupredoxin, which has a distorted tetrahedral active site with the ligands provided by two histidines, a cysteine and a methionine. The isotropic shifts of the resonances in these spectra are compared with those of Co(II) and Ni(II) azurin. A number of interesting similarities and differences are found. The coordination of the metal by the two equatorial histidine ligands is very similar in both proteins. The interaction between the introduced metal and the thiolate sulfur of the equatorial cysteine ligan…