homocysteine

(redirected from homocystine)
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Related to homocystine: C reactive protein, Methylmalonic acid, homocysteine test

homocysteine

[¦hä·mə′sis·tēn]
(biochemistry)
C4H9O2NS An amino acid formed in animals by demethylation of methionine.
References in periodicals archive ?
To detect Hg(II) ion selectively, we modified the surface of the gold nanoparticle with mercaptopropionic acid (MPA) and homocystine (bound to the gold nanoparticle surface through Au-S bond) and we added a chelating ligand 2,6-pyridinedicarboxylic acid (PDCA), to the solution, as we discussed before.
The biochemical data were virtually diagnostic of homocystinuria [OMIM (3) (Online Mendelian Inheritance in Man) 236200], a term historically used to describe inborn errors of metabolism characterized by excessive excretion of homocystine in urine and high concentrations of total plasma homocysteine.
Isotopically labeled MMA and homocystine standards were purchased from Cambridge Isotope Laboratories and isotopically labeled MCA from CDN Isotopes.
HHCY was induced by 2 different diets (Altromin) that were administered for 12 weeks: methionine at 24 g/kg food and homocystine at 20 g/kg food.
The 2 other groups were fed with homocystine-enriched diets, containing 10 g (Hcy1) or 20 g (Hcy2) homocystine (Sigma) per kg food (corresponding to 1% and 2% Hcy).
Relative roles of albumin and ceruloplasmin in the formation of homocystine, homocysteine-cysteine-mixed disulfide, and cystine in circulation.
The remaining unbound HCY combines by oxidation, either with itself to form the dimer homocystine or with cysteine to form the mixed disulfide cysteineHCY.
More than 80% of Hcy is found in plasma, mostly conjugated to proteins through disulfide bonding or as symmetrical disulfide homocystine, as mixed disulfide Hcy-Cys, or as a free thiol (<2%) (1,5).
CBS deficiency leads to markedly increased concentrations of homocystine in urine and total homocysteine (tHcy) and methionine in blood (3, 8).
Homocystinuria refers to the rare inborn errors of metabolism leading to urinary excretion of large amounts of homocystine combined with severely increased plasma tHcy concentrations, usually >100 [micro]mol/L (25).
Only a few metabolites [citrulline, homocystine, argininosuccinate (ASA), glycyl-proline, and 8-aminolevulinate] had CVs >15% at the higher concentration.
Such methods are based on the reduction of protein-bound homocysteine, homocystine, and mixed disulfides to reduced homocysteine, followed by derivatization of the reduced homocysteine with thiol-specific fluorogenic reagents.