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.cysteine is metabolism 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 methionine and glutathione metabolism as well as pantothenate/coenzyme A biosynthesis.
| Enzyme | Cofactor/Additional Reactant | → | Products |
|---|---|---|---|
| cysteine dioxygenase | iron | → | cysteine sulfinic acid |
| amino-acid racemase | pyridoxal phosphate | → | D-cysteine |
| cysteine lyase | pyridoxal phosphate/sulfite | → | L-cysteate/hydrogen sulfide |
| cystathionine γ-lyase | pyridoxal phosphate | → | NH3/H2S |
| cysteine—tRNA ligase | → | L-cysteinyl-tRNACys | |
| cystine reductase | NAD+ | → | L-cystine/NADH and H+ |
| cysteine transaminase | pyridoxal phosphate/alpha-ketoglutaric acid | → | 3-mercapto-pyruvate/L-glutamate |
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 |
|---|---|---|---|
| O-acetyl-L-serine/hydrogen sulfide | → | cysteine synthase | Pyridoxal phosphate |
| L-cystine/2 glutathione | → | glutathione-cystine transhydrogenase | |
| cystathionine | → | cystathionine γ-lyase | pyridoxal phosphate |
| 3-mercapto-pyruvate | → | cysteine transaminase | pyridoxal phosphate |
gollark: > Note: right now autofree is hidden behind the -autofree flag. It will be enabled by default in V 0.3. If autofree is not used, V programs will leak memory.
gollark: You can't use the accursed resultoptional hybrid they have in situations when you have a value which *can* actually be nonexistent for whatever reasons, and it's actually `Result<T, string>` constantly.
gollark: Because they aren't really doing "option" and "result" at that point as much as a bizarre special-cased thing which is basically just indirected exceptions.
gollark: > Generics> At the moment only one type parameter named T is supported.
gollark: > V combines Option and Result into one type, so you don't need to decide which one to use.What an amazing design.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.