L-Homocystine
IUPAC 名称
2-amino-4-{[(3S)-3-amino-3-carboxypropyl]disulfanyl}butanoic acid
描述
Homocystine is the double-bonded form of homocysteine, but it occurs only transiently before being converted to the harmless cystathionine via a vitamin B6-dependent enzyme.
Homocystine and homocysteine-cysteine mixed disulfide account for >98% of total homocysteine in plasma from healthy individuals. (PMID 11592966)
Oxidation of low-density lipoprotein (LDL) is thought to be a major factor in the pathophysiology of atherosclerosis. Elevated plasma homocysteine is an accepted risk factor for atherosclerosis, and may act through LDL oxidation, although this is controversial. However, the major thiol in plasma is cysteine, which is present at concentrations approximately 10 times greater than homocysteine; therefore homocystine in plasma is insignificant, and consequently homocystine is unlikely to influence LDL oxidation in vivo. (PMID 14732479)
Increasing evidence supports a role for an elevation of homocysteine in schizophrenia. It has been demonstrated that neural tube defects are related to a genetic defect in homocysteine metabolism. Sufficient intake of folic acid is believed to reduce this risk by enhancing methylation of homocysteine and its conversion to methionine, thereby compensating for this genetic defect. Plasma homocysteine levels are elevated when folate levels are in the lower half of the normal range. (PMID 16143442 ) [HMDB]
异构
NC(CCSSCC[C@H](N)C(O)=O)C(O)=O
InChI标识符
InChI=1S/C8H16N2O4S2/c9-5(7(11)12)1-3-15-16-4-2-6(10)8(13)14/h5-6H,1-4,9-10H2,(H,11,12)(H,13,14)/t5-,6?/m0/s1
键
ZTVZLYBCZNMWCF-ZBHICJROSA-N