Wikiversity has learning resources about Homocysteine Homocysteine MS Spectrum Homocysteine at Lab Tests Online Homocysteine: ... Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors. It has been proposed that both homocysteine and ... Homocysteine exists at neutral pH values as a zwitterion. Homocysteine is biosynthesized naturally via a multi-step process. ... Homocysteine can cyclize to give homocysteine thiolactone, a five-membered heterocycle. Because of this "self-looping" reaction ...

The enzyme homocysteine desulfhydrase (EC 4.4.1.2) catalyzes the chemical reaction L-homocysteine + H2O = hydrogen sulfide + ... Other names in common use include homocysteine desulfurase, L-homocysteine hydrogen-sulfide-lyase (deaminating). This enzyme ... The systematic name of this enzyme class is L-homocysteine hydrogen-sulfide-lyase (deaminating; 2-oxobutanoate-forming). ... NH3 + 2-oxobutanoate (overall reaction) (1a) L-homocysteine = hydrogen sulfide + 2-aminobut-2-enoate (1b) 2-aminobut-2-enoate ...

... may refer to: Homocysteine S-methyltransferase 5-methyltetrahydropteroyltriglutamate-homocysteine S- ...

... homocysteine methylase, homocysteine methyltransferase, homocysteine transmethylase, L-homocysteine S-methyltransferase, S- ... S-adenosylmethionine-homocysteine transmethylase, and S-adenosylmethionine:homocysteine methyltransferase. Balish E, Shapiro SK ... S-methylmethionine homocysteine transmethylase, adenosylmethionine transmethylase, methylmethionine:homocysteine ... In enzymology, a homocysteine S-methyltransferase (EC 2.1.1.10) is an enzyme that catalyzes the chemical reaction S- ...

In the field of enzymology, a betaine-homocysteine S-methyltransferase also known as betaine-homocysteine methyltransferase ( ... Pajares MA, Pérez-Sala D (December 2006). "Betaine homocysteine S-methyltransferase: just a regulator of homocysteine ... "Betaine-homocysteine S-methyltransferase-2 is an S-methylmethionine-homocysteine methyltransferase". J. Biol. Chem. 283 (14): ... Betaine+Homocysteine+Methyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) EC 2.1.1.5 ...

... (SAH) is the biosynthetic precursor to homocysteine. SAH is formed by the demethylation of S-adenosyl ... Two S-adenosyl-L-homocysteine cofactor products can bind the active site of DNA methyltransferase 3B and prevent the DNA duplex ... BioCYC E.Coli K-12 Compound: S-adenosyl-L-homocysteine v t e (ECHA InfoCard ID from Wikidata, Articles containing unverified ... Finkelstein JD (2000). "Pathways and regulation of homocysteine metabolism in mammals". Seminars in Thrombosis and Hemostasis. ...

Other names in common use include dimethylthetin-homocysteine methyltransferase, and thetin-homocysteine methylpherase. KLEE WA ... In enzymology, a thetin-homocysteine S-methyltransferase (EC 2.1.1.3) is an enzyme that catalyzes the chemical reaction ... MAW GA (1956). "Thetin-homocysteine transmethylase; a preliminary manometric study of the enzyme from rat liver". Biochem. J. ... MAW GA (1958). "Thetin-homocysteine transmethylase; some further characteristics of the enzyme from rat liver". Biochem. J. 70 ...

Homocysteine is coordinated to a zinc ion, as initially suggested by spectroscopy and mutagenesis . Pejchal R, Ludwig ML ( ... The systematic name of this enzyme class is 5-methyltetrahydropteroyltri-L-glutamate:L-homocysteine S-methyltransferase. Other ... In enzymology, a 5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase (EC 2.1.1.14) is an enzyme that ... The role of zinc in the methylation of homocysteine". J. Am. Chem. Soc. 120 (33): 8410-8416. doi:10.1021/ja980581g. Portal: ...

... responsible for the reversible hydration of S-adenosyl-L-homocysteine into adenosine and homocysteine. AdoHcyase is a ... S-adenosyl-L-homocysteine hydrolase (EC 3.3.1.1) (AdoHcyase) is an enzyme of the activated methyl cycle, ... Sganga MW, Aksamit RR, Cantoni GL, Bauer CE (1992). "Mutational and nucleotide sequence analysis of S-adenosyl-L-homocysteine ...

This is hydrolysed to homocysteine and adenosine by S-adenosylhomocysteine hydrolase EC 3.3.1.1 and the homocysteine recycled ... that use SAM as a substrate produce S-adenosyl homocysteine as a product. S-Adenosyl homocysteine is a strong negative ... Finkelstein J, Martin J (2000). "Homocysteine". The International Journal of Biochemistry & Cell Biology. 32 (4): 385-9. doi: ... also cogenerates methionine S-adenosyl homocysteine, releasing methyl radical methylthioadenosine (SMT), homoalanine radical ...

Cysteine-related metabolites homocysteine and taurine are other sulfur-containing amino acids that are similar in structure, ... ISBN 978-1-57259-153-0. Selhub, J. (1 July 1999). "Homocysteine metabolism". Annual Review of Nutrition. 19 (1): 217-246. doi: ...

Prolactin - Deficiency (childhood). homocysteine - Excess. Megaloblastic anemia (MA) is associated with GSE and is believed to ...

PEMT is also a significant source and regulator of plasma homocysteine, which can be secreted or converted to methionine or ... High levels of homocysteine are linked to cardiovascular disease and atherosclerosis, particularly coronary artery disease. ... Refsum H, Ueland PM, Nygård O, Vollset SE (1998). "Homocysteine and cardiovascular disease". Annual Review of Medicine. 49: 31- ... PEMT modulates levels of blood plasma homocysteine, which is either secreted or converted to methionine or cysteine. ...

In common forms of MTHFR deficiency, elevated plasma homocysteine levels have sometimes been treated with Vitamin B12 and low ... Den Heijer, M.; Lewington, S.; Clarke, R. (2005). "Homocysteine, MTHFR and risk of venous thrombosis: a meta-analysis of ... Although this treatment significantly decreases the serum levels of homocysteine, this treatment is not thought to improve ... Casas, Juan P.; Bautista, Leonelo E.; Smeeth, Liam; Sharma, Pankaj; Hingorani, Aroon D. (2005). "Homocysteine and stroke: ...

Homocysteine is an intermediate that is responsible for maintaining methylation reactions in critical metabolic processes. It ... This reaction is a critical step in the conversion of homocysteine to methionine. The resulting product is a methyl donor that ... After examining Type 2 diabetes patients, it was found that levels of homocysteine were exceptionally high when compared to ... Medina MÁ, Urdiales JL, Amores-Sánchez MI (2001). "Roles of homocysteine in cell metabolism Old and new functions". European ...

... this step is performed by homocysteine methyltransferase or betaine-homocysteine S-methyltransferase.) Although mammals cannot ... Homocysteine can also be remethylated using glycine betaine (N,N,N-trimethylglycine, TMG) to methionine via the enzyme betaine- ... If homocysteine is produced, the thiol group is methylated, yielding methionine. Two methionine synthases are known; one is ... Homocysteine can be converted to cysteine. (5) Cystathionine-β-synthase (an enzyme which requires pyridoxal phosphate, the ...

Deficiency in folate can cause an elevation of homocysteine within the blood, as the clearance of homocysteine requires ... Elevated homocysteine has been associated with increased risk of vascular events, as well as dementia. Differences lie in the ... Homocysteine Lowering Trialists' Collaboration (2005). "Dose-dependent effects of folic acid on blood concentrations of ... Quadri, P; Fragiacomo, C; Pezzati, R; Zanda, E; Forloni, G; Tettamanti, M; Lucca, U (2004). "Homocysteine, folate, and vitamin ...

"Homocysteine/Hypertension & Vascular Lesion Formation". www.labome.org. Retrieved 2008-03-09. (All articles with dead external ...

"Detection of Homocysteine and Cysteine". Journal of the American Chemical Society. 127 (45): 15949-15958. doi:10.1021/ja054962n ...

Its biological function is hydrolysis of the reactive electrophile homocysteine thiolactone. Another of its activities is ... "Protective Mechanisms against Homocysteine Toxicity". The Journal of Biological Chemistry. 281 (32): 22485-22492. doi:10.1074/ ...

Homocysteine is unable to give ring closure and the color does not change. Organic Syntheses, Coll. Vol. 6, p.901 (1988); Vol. ... In one potential application, p-aminocinnamaldehyde is able to differentiate between cysteine and homocysteine. With cysteine, ... "Detection of Homocysteine and Cysteine". Journal of the American Chemical Society. 127 (45): 15949-15958. doi:10.1021/ja054962n ...

Increased homocysteine levels suggest tissue folate deficiency, but homocysteine is also affected by vitamin B12 and vitamin B6 ... Conversion of homocysteine to methionine requires folate and vitamin B12. Elevated plasma homocysteine and low folate are ... in a reaction catalyzed by homocysteine methyltransferase, to methionine. A defect in homocysteine methyltransferase or a ... Cobalamin (vitamin B12) deficiency may lead to folate deficiency, which, in turn, increases homocysteine levels and may result ...

June 2006). "Homocysteine, hRIP3 and congenital cardiovascular malformations". Anatomy and Embryology. 211 (3): 203-212. doi: ...

The coproduct is S-adenosyl homocysteine. The biological roles of S-methylmethionine are not well understood. Speculated roles ...

... homocysteine levels rise and the pathway that converts homocysteine->methionine->SAM becomes the primary method of homocysteine ... Homocysteine metabolism occurs via two pathways. One pathway breaks homocysteine into methionine and than into S- ... Type I diabetes is characterized by global hypermethylation that arises as a result of alterations to homocysteine metabolism. ... adenosylmethuionine(SAM). Another pathway, the transsulfuration pathway, through numerous steps breaks homocysteine down into ...

If B12 is absent, the forward reaction of homocysteine to methionine does not occur, homocysteine concentrations increase, and ... Homocysteine (homocysteine to methionine, catalysed by methionine synthase) leading to hyperhomocysteinemia Methylmalonic acid ... and result in raised homocysteine levels. There is much evidence linking elevated homocysteine concentrations with an increased ... Dhonukshe-Rutten RA, Pluijm SM, de Groot LC, Lips P, Smit JH, van Staveren WA (June 2005). "Homocysteine and vitamin B12 status ...

Gambhir, J. K. (2000). "Homocysteine metabolism in health and disease". Indian Heart Journal. 52 (7 Suppl): S9-15. PMID ... Her works spans across numerous fields such as nephropathy, estrogen deficiency effects, lipoproteins, homocysteine and ...

Krajčovičová-Kudláčková, M.; Blažíček, P.; Kopčová, J.; Béderová, A.; Babinská, K. (2000). "Homocysteine Levels in Vegetarians ...

Homocysteine - Plasma - Amyloid beta - Alzheimer's disease". Neurochemical Research. 32 (4-5): 775-781. doi:10.1007/s11064-006- ...

... is derived from cysteine (and homocysteine). In mammals, the biosynthesis of hypotaurine from cysteine occurs in ...