View source for Arginine and proline metabolism

'''Arginine and proline metabolism''' is one of the central pathways for the biosynthesis of the amino acids [[arginine]] and [[proline]] from [[glutamate]]. The pathways linking arginine, glutamate, and proline are bidirectional. Thus, the net utilization or production of these amino acids is highly dependent on cell type and developmental stage.
Altered proline metabolism has been linked to metastasis formation in breast cancer.<ref>{{Cite journal | doi=10.1038/ncomms15267| pmid=28492237| pmc=5437289| title=Proline metabolism supports metastasis formation and could be inhibited to selectively target metastasizing cancer cells| journal=Nature Communications| volume=8| pages=15267| year=2017| last1=Elia| first1=Ilaria| last2=Broekaert| first2=Dorien| last3=Christen| first3=Stefan| last4=Boon| first4=Ruben| last5=Radaelli| first5=Enrico| last6=Orth| first6=Martin F.| last7=Verfaillie| first7=Catherine| last8=Grünewald| first8=Thomas G. P.| last9=Fendt| first9=Sarah-Maria| bibcode=2017NatCo...815267E}}</ref>
==Reactions==
Proline is biosynthetically derived from the amino acid <small>L</small>-[[glutamate]].  [[Glutamate-5-semialdehyde]] is first formed by [[glutamate 5-kinase]] (ATP-dependent) and [[glutamate-5-semialdehyde dehydrogenase]] (which requires NADH or NADPH). This can then either spontaneously cyclize to form [[1-pyrroline-5-carboxylic acid]], which is reduced to proline by [[pyrroline-5-carboxylate reductase]] (using NADH or NADPH), or turned into [[ornithine]] by [[ornithine aminotransferase]], followed by cyclisation by [[ornithine cyclodeaminase]] to form proline.<ref>{{Lehninger3rd}}.</ref>
[[Citrulline]] is made from [[ornithine]] and [[carbamoyl phosphate]] by [[ornithine carbamoyltransferase]]. Arginine is then synthesized from citrulline in the [[urea cycle]] by the sequential action of the cytosolic enzymes [[argininosuccinate synthetase]] (ASS) and [[argininosuccinate lyase]] (ASL).
==References==
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[[Category:Proteinogenic amino acids]]
[[Category:Basic amino acids]]