Homocysteine thiolactone is a toxic metabolite produced from homocysteine by amino-acyl t-RNA synthetase in error editing reaction. The basic cause of toxicity of homocysteine thiolactone is believed to be due to the adduct formation with lysine residues (known as protein N-homocysteinylation) leading to protein aggregation and loss of enzyme function. There was no data available until now that...

Elevated concentration of homocysteine (Hcy) in human tissues, definied as hyperhomocysteinemia has been correlated with some diseases, such as cardiovascular, neurodegenerative, and kidney disorders. Homocysteine occurs in human blood plasma in several forms, including the most reactive one, the homocysteine thiolactone (HTL) - a cyclic thioester, which represents up to 0.29% of total plasma H...

Elevated levels of homocysteine are associated with several major diseases. However, it is not clear whether homocysteine is a marker or a causative agent. The majority (ca. 80%) of the homocysteine present in humans is protein bound. The study of the posttranslational modification of proteins by homocysteine and its cyclic congener, homocysteine thiolactone, is emerging as an area of great cur...

A series of fully bio-based poly(ester- alt -thioether)s are efficiently synthesized by organo-catalyzed alternating ring-opening copolymerizations eugenol-derived monomers, vanillin glycidyl ether and N -acetyl homocysteine thiolactone.

Activation of amino acid homocysteine was compared with that of methionine in rabbit crude liver extracts and purified multi-enzyme complex of aminoacyl-tRNA synthetases. Activation was studied by measuring the incorporation of radioactive amino acid into unlabelled trichloroacetic-acid insoluble materials in the absence of protein synthesis. Homocysteine synthetase activity was found in the cr...

S-Adenosylhomocysteine hydrolase of mammalian hearts from different species is exclusively a cytosolic enzyme. The apparent Km for the guinea-pig enzyme was 2.9 microM (synthesis) and 0.39 microM (hydrolysis). Perfusion of isolated guinea-pig hearts for 120 min with L-homocysteine thiolactone (0.23 mM) and adenosine (0.1 mM), in the presence of erythro-9-(2-hydroxynon-3-yl)adenine to inhibit ad...

Elevated blood concentrations of homocysteine have been well established as a risk factor for cardiovascular diseases and neuropsychiatric diseases, yet the etiologic relationship of homocysteine to these disorders remains poorly understood. Protein N-homocysteinylation has been hypothesized as a contributing factor; however, it has not been examined globally owing to the lack of suitable detec...

BACKGROUND A metabolite of homocysteine (Hcy), the thioester Hcy-thiolactone, has been implicated in coronary heart disease in humans. Because inadvertent reactions of Hcy-thiolactone with proteins can lead to cell and tissue damage, the ability to detoxify or eliminate Hcy-thiolactone is essential for biological integrity. We examined the hypothesis that the human body eliminates Hcy-thiolacto...

The effects of ethanol on epilepsy are very complex. Ethanol can have depressant as well as excitatory effect on different animal models of epilepsy. Systemic administration of homocysteine can trigger seizures. The aim of the present study was to examine the changes of total spectral power density after ethanol alone and together with homocysteine thiolactone in adult rats. Adult male Wistar r...

OBJECTIVES: The aim of this study was to determine the effects of acute, single boost of physical activity on seizures induced by homocysteine thiolactone in rats, using treadmill for small experimental animals as a paradigm of physical activity. MATERIAL AND METHODS: After adaptation to the treadmill, Wistar albino rats were randomly divided into acute physical activity and sedentary group. An...