Editing Alanine (section)

==Sources==

===Biosynthesis===
Alanine can be synthesized from [[pyruvate]] and [[Branched-chain amino acids|branched chain amino acids]] such as [[valine]], [[leucine]], and [[isoleucine]].

Alanine is produced by [[reductive amination]] of [[pyruvate]], a two-step process. In the first step, [[Alpha-Ketoglutaric acid|α-ketoglutarate]], [[ammonia]] and [[NADH]] are converted by [[glutamate dehydrogenase]] to [[glutamate]], NAD<sup>+</sup> and water. In the second step, the amino group of the newly formed glutamate is transferred to pyruvate by an [[aminotransferase]] enzyme, regenerating the α-ketoglutarate, and converting the pyruvate to alanine. The net result is that pyruvate and ammonia are converted to alanine, consuming one [[reducing equivalent]].<ref name=":0" />{{rp|721}} Because [[transamination]] reactions are readily reversible and pyruvate is present in all cells, alanine can be easily formed and thus has close links to metabolic pathways such as [[glycolysis]], [[gluconeogenesis]], and the [[citric acid cycle]].<ref>{{Citation |last1=Melkonian |first1=Erica A. |title=Physiology, Gluconeogenesis |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK541119/ |work=StatPearls |access-date=2023-07-09 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=31082163 |last2=Asuka |first2=Edinen |last3=Schury |first3=Mark P.}}</ref>

===Chemical synthesis===
{{See also|Hell–Volhard–Zelinsky halogenation}}
<small>L</small>-Alanine is produced industrially by decarboxylation of [[L-aspartate|<small>L</small>-aspartate]] by the action of [[aspartate 4-decarboxylase]].  Fermentation routes to <small>L</small>-alanine are complicated by [[alanine racemase]].<ref>{{Ullmann| vauthors = Drauz K, Grayson IG, Kleemann A, Krimmer HP, Leuchtenberger W, Weckbecker C |year=2006|doi=10.1002/14356007.a02_057.pub2}}</ref>

[[Racemic]] alanine can be prepared by the condensation of [[acetaldehyde]] with [[ammonium chloride]] in the presence of [[sodium cyanide]] by the [[Strecker amino acid synthesis|Strecker reaction]],<ref>{{OrgSynth | vauthors = Kendall EC, McKenzie BF | title = ''dl''-Alanine | prep = cv1p0021 | volume = 9 | pages = 4 | year = 1929 | collvol = 1 | collvolpages = 21 | doi = 10.15227/orgsyn.009.0004}}.</ref>
<!--- Note: This Org Synth manuscript is in two parts; the Kendall and McKenzie part used above relates to the Strecker synthesis, whilst the second part by Tobie and Ayres relates to preparing alanine from 2-bromopropanoic acid.  Please be careful if checking / changing these reference, which do share most citation details. --->
:[[File:Synthesis_of_alanine_-_1.png|415px]]

or by the [[ammonolysis]] of [[2-bromopropanoic acid]].<ref>{{OrgSynth | vauthors = Tobie WC, Ayres GB | title = ''dl''-Alanine | prep = cv1p0021 | year = 1941 | collvol = 1 | collvolpages = 21 | doi = 10.15227/orgsyn.009.0004 }}</ref> <!---Note above applies here too--->
:[[File:Synthesis_of_alanine_-_2.png|300px]]

=== Degradation ===
Alanine is broken down by [[oxidative deamination]], the inverse reaction of the reductive amination reaction described above, catalyzed by the same enzymes. The direction of the process is largely controlled by the relative concentration of the substrates and products of the reactions involved.<ref name=":0" />{{rp|721}}