From Surf Wiki (app.surf) — the open knowledge base

Cysteine metabolism

Cysteine metabolism refers to the biological pathways that consume or create cysteine. The pathways of different amino acids and other metabolites interweave and overlap to creating complex systems.

Human cysteine metabolism

In human cysteine metabolism, L-cysteine is consumed in several ways as shown below. L-Cysteine is also consumed in pantothenate/coenzyme A biosynthesis.

Enzyme	→	Products	Cofactor/Additional Reactant
cysteine dioxygenase	→	cysteine sulfinic acid	iron
serine racemase	→	D-cysteine	pyridoxal phosphate
cysteine lyase	→	L-cysteate/hydrogen sulfide	pyridoxal phosphate/sulfite
vauthors = Sun Q, Collins R, Huang S, Holmberg-Schiavone L, Anand GS, Tan CH, van-den-Berg S, Deng LW, Moore PK, Karlberg T, Sivaraman J	display-authors = 6	title = Structural basis for the inhibition mechanism of human cystathionine gamma-lyase, an enzyme responsible for the production of H(2)S	language = English	journal = The Journal of Biological Chemistry	volume = 284	issue = 5	pages = 3076–3085	date = January 2009	pmid = 19019829	doi = 10.1074/jbc.M805459200	doi-access = free }}	→	pyruvate/NH3/H2S	pyridoxal phosphate
cysteine—tRNA ligase	→	L-cysteinyl-tRNACys
cystine reductase	→	L-cystine/NADH and H+	NAD+
vauthors = Hipólito A, Nunes SC, Vicente JB, Serpa J	title = Cysteine Aminotransferase (CAT): A Pivotal Sponsor in Metabolic Remodeling and an Ally of 3-Mercaptopyruvate Sulfurtransferase (MST) in Cancer	journal = Molecules	volume = 25	issue = 17	page = 3984	date = September 2020	pmid = 32882966	pmc = 7504796	doi = 10.3390/molecules25173984	doi-access = free }}	→	[3-mercapto-pyruvate](3-mercapto-pyruvate)/L-glutamate	pyridoxal phosphate/alpha-ketoglutaric acid
glutamate–cysteine ligase	→	γ-glutamyl cysteine/ADP and Pi	ATP

L-Cysteine is the product of several processes as well. In addition to the reactions below, L-cysteine is also a product of glycine, serine, and threonine metabolism.

Reactants	→	Enzyme	Cofactors	Notes
O-acetyl-L-serine/hydrogen sulfide	→	cysteine synthase	pyridoxal phosphate	not present in humans
L-cystine/2 glutathione	→	glutathione-cystine transhydrogenase
cystathionine	→	cystathionine γ-lyase	pyridoxal phosphate
[3-mercapto-pyruvate](3-mercapto-pyruvate)	→	cysteine transaminase	pyridoxal phosphate

References

(May 2009). "Cysteine dioxygenase: a robust system for regulation of cellular cysteine levels". Amino Acids.
(March 2023). "Mammalian D-Cysteine: A new addition to the growing family of biologically relevant D-amino acids". Chirality.
(February 1969). "Reactions catalysed by cysteine lyase from the yolk sac of chicken embryo". Biochimica et Biophysica Acta (BBA) - Enzymology.
(January 2009). "Structural basis for the inhibition mechanism of human cystathionine gamma-lyase, an enzyme responsible for the production of H(2)S". The Journal of Biological Chemistry.
(December 1964). "The separation and partial purification of aminoacyl-RNA synthetases from Escherichia coli". Biochimica et Biophysica Acta (BBA) - Specialized Section on Nucleic Acids and Related Subjects.
(September 1978). "Cystine reductase in the dimorphic fungus Histoplasma capsulatum". Journal of Bacteriology.
(September 2020). "Cysteine Aminotransferase (CAT): A Pivotal Sponsor in Metabolic Remodeling and an Ally of 3-Mercaptopyruvate Sulfurtransferase (MST) in Cancer". Molecules.
(October 2005). "Glutamate cysteine ligase catalysis: dependence on ATP and modifier subunit for regulation of tissue glutathione levels". The Journal of Biological Chemistry.
(May 1969). "Purification and characterization of cysteine synthetase, a bifunctional protein complex, from Salmonella typhimurium". The Journal of Biological Chemistry.
(April 1968). "A thiol-disulfide transhydrogenase from yeast". The Journal of Biological Chemistry.

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

alpha-amino-acids sulfur-metabolism sulfur-amino-acids

Want to explore this topic further?

Ask Mako anything about Cysteine metabolism — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report