While it is well known that introduction of Pro residues into the interior of protein alpha-helices is destabilizing, there have been few studies that have examined the structural and thermodynamic effects of the replacement of a Pro residue in the interior of a protein alpha-helix. We have previously reported an increase in stability in the P40S mutant of Escherichia coli thioredoxin of 1-1.5 ...

beta-Amyloid peptide (A beta), the main constituent of senile plaques and diffuse amyloid deposits in Alzheimer's diseased brain, was shown to initiate the development of oxidative stress in neuronal cell cultures. Toxic lots of A beta form free radical species in aqueous solution. It was proposed that A beta-derived free radicals can directly damage cell proteins via oxidative modification. Re...

BACKGROUND Lipofuscin (LF) is formed during lipid peroxidation and sugar glycosylation by carbonyl-amino crosslinks with biomacrolecules, and accumulates slowly within postmitotic cells. The environmental pollution, modern dietary culture and lifestyle changes have been found to be the major sources of reactive carbonyl compounds in vivo. Irreversible carbonyl-amino crosslinks induced by carbon...

This study aims to investigate the optimized structure and parameters of carisoprodol from DFT/B3LYP/6-31G(d,p) level theory. The molecular electrostatic potential (MEP) map signifies that positive across hydrogen amine group (NH2) negative around carbonyl groups (C=O). HOMO-LUMO energy gap was found be 8.1064 eV. global local reactivity describe possible chemical reactive sites in molecule. to...

Exposure of human plasma to gas-phase (but not to whole) cigarette smoke (CS) produces oxidative damage to lipids [Frei, Forte, Ames & Cross (1991) Biochem. J. 277, 133-138], which is prevented by ascorbic acid. The ability of CS to induce protein damage was measured by the carbonyl assay and by loss of enzyme activity and protein -SH groups. Both whole and gas-phase CS caused formation of carb...

Although, increased oxidative stress and hypomethylation of long interspersed nuclear element-1 (LINE-1) associate with bladder cancer (BCa) development, the relationship between these alterations is unknown. We evaluated the oxidative stress and hypomethylation of the LINE-1 in 61 BCa patients and 45 normal individuals. To measure the methylation levels and to differentiate the LINE-1 loci int...

Recent work indicates that free radical-mediated lipid peroxidation takes place within the diaphragm on strenuous contraction. This phenomenon has only been demonstrated using fairly artificial experimental models and has not been studied during the type of sustained respiratory loading typically seen in patients with lung disease. The purpose of the present study was to measure the levels of s...

Carnosine has been shown to react with low-molecular-weight aldehydes and ketones and has been proposed as a naturally occurring anti-glycating agent. It is suggested here that carnosine can also react with ("carnosinylate") proteins bearing carbonyl groups, and evidence supporting this idea is presented. Accumulation of protein carbonyl groups is associated with cellular ageing resulting from ...

RATIONALE Oxidative stress is involved in the skeletal muscle dysfunction observed in patients with severe chronic obstructive pulmonary disease (COPD). We hypothesized that the diaphragms of such patients might generate greater levels of oxidants than those neutralized by antioxidants. OBJECTIVES To assess the levels of both oxidative and nitrosative stress and different antioxidants in the ...