UNLABELLED S-Adenosyl-L-homocysteine, the product of S-adenosyl-L-methionine (SAM) methyltransferases, is known to be a strong feedback inhibitor of these enzymes. A hydrolase specific for S-adenosyl-L-homocysteine produces L-homocysteine, which is remethylated to methionine and can be used to regenerate SAM. Here, we show that the annotated S-adenosyl-L-homocysteine hydrolase in Methanocaldoco...

We administered reduced L-homocysteine perorally (67 mumol/kg of body wt) to 12 healthy subjects and injected the same dose into one person, and determined the kinetics of the alterations in reduced, oxidized, and protein-bound concentrations of homocysteine, cysteine, and cysteinylglycine. After oral intake, reduced homocysteine increased rapidly (tmax < or = 15 min), reaching concentrations [...

Recent studies have documented the importance of lipids and lipoproteins as determinants of serum total homocysteine concentrations in persons with myocardial infarction, and in healthy subjects. Associations between various biological systems and total homocysteine have also been reported. However, some of these associations are poorly understood. The purpose of our study was to measure serum ...

Background: An elevated homocysteine level is an independent risk factor for cardiovascular disorders. Psoriatic patients have an increased risk of cardiovascular diseases; In addition, hyperhomocysteinemia is a complication of methotrexate treatment. We undertook a study to evaluate the plasma levels of homocysteine, vitamin B12 and folate in patients with psoriasis before and after short-term...

Homocysteine is a sulfur containing amino acid that is created in the body from Methionine, an essential amino acid derived solely from dietary intake. Methionine is metabolized into Homocysteine via an intermediate, S-adenosyl Methionine. Homocysteine can be metabolized to produce cysteine, a nonessential sulfur-containing amino acid, or it can be remethylated to Methionine. Whether the body n...

Monshi Karimi AR1, Mohtadi-nia J2, Farhodi M3 1. M.Sc Student of nutritional sciences, Faculty of Health, Tabriz University of Medical Sciences 2. Associated professor, Department of Nutritional, Faculty of Health, Tabriz University of Medical Sciences 3. Assistant professor, Department of Internal, Faculty of medicine, Tabriz University of Medical Sciences Abstract Background: Isc...

Objective: To observe the concentration of serum homocysteine in intellectuals and the related influential factors. Methods: The concentrations serum homocysteine and saliva cortisol were measured in 138 intellectuals from three cities, Tianjin, Guangzhou and Chengdu in China. All the subjects had senior titles of technical post, aged 40-69 years. Results: The mean value of serum homocysteine c...

objective: an association between high homocysteine levels and proteinuria in diabetic nephropathy has been shown. on the other hand, supplementation with folic acid lowers homocysteine concentration. we have studied the effects of folic acid supplementation on proteinuria in type 2 diabetic patients with overt proteinuria. materials and methods: forty five (29 men and 16 women) type 2 diabetic...

An elevated level of homocysteine, a thiol amino acid, is associated with various complex disorders. The cellular effects of homocysteine and its precursors Sadenosyl homocysteine (SAH) and Sadenosyl methionine (SAM) are however poorly understood. We used Saccharomyces cerevisiae as a model to understand the basis of pathogenicity induced by homocysteine and its precursors. Both homocysteine an...