Hyperhomocysteinemia and insulin resistance are independent factors for cardiovascular disease. Most of the angiotoxic effects of homocysteine are related to the formation of homocysteine thiolactone and the consequent increase in oxidative stress. We have recently found that homocysteine thiolactone inhibits insulin receptor tyrosine kinase activity, which results in decreased phosphatidylinos...

Previous in vitro studies have established a pre-transfer proofreading mechanism for editing of homocysteine by bacterial methionyl-, isoleucyl-, and valyl-tRNA synthetases. The unusual feature of the editing is the formation of a distinct compound, homocysteine thiolactone. Now, two-dimensional TLC analysis of 35S-labeled amino acids extracted from cultures of the bacterium Escherichia coli re...

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...

Influence of folic acid on the CNS is still unclear. Folate has a neuroprotective effect, while on the other hand excess folate can exacerbate seizures in epileptics. The aim of the present study was to examine the effect of subchronic administration of folic acid on behavioural and electroencephalographic (EEG) characteristics of DL homocysteine thiolactone induced seizures in adult rats. The ...

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...

Plasma amino acid response of wethers to abomasal infusions of DL-methionine (DLM), DL-homocysteine thiolactone-HCl (HCTL) and N-acetyl-DL-methionine (NAM), in vivo rumen stability of the latter two methionine analogs and preintestinal absorption of HCTL were studied. The daily infusion of 1.06 g of DLM elevated molar percentage of methionine and lysine in plasma'and decreased molar percentage ...

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...