The INDIVIDUALIST

A Wiki about biochemical individuality

Biochemistry

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Description

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

Discussion

Human cysteine metabolism

In human cysteine metabolism, L-cysteine is consumed in several ways as shown below. L-cysteine is also consumed in methionine? and glutathione metabolism as well as pantothenate/CoA biosynthesis.

L-cysteine consumption pathways
enzyme product
cysteine dioxygenase 3-sulfino-L-alanine (or cysteine sulfinic acid)
amino-acid racemase D-cysteine
cysteine lyase L-cysteate
cysteine—tRNA ligase L-cysteinyl-tRNACys
cystine reductase L-cystine
cysteine transaminase 3-mercapto-pyruvate

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.

L-cysteine production pathways
starting chemical enzyme
O-acetyl-L-serine cysteine synthase
L-cystine glutathione-cystine transhydrogenase
pyruvate cystathionine γ-lyase
3-mercapto-pyruvate cysteine transaminase

Links

Attribution

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