View source for Biology:Oxidative deamination

{{Short description|Metabolic process}}
'''Oxidative deamination''' is a form of [[Biology:Deamination|deamination]] that generates [[Chemistry:Keto acid|α-keto acids]] and other oxidized products from amine-containing compounds, and occurs primarily in the [[Biology:Liver|liver]].<ref>{{Cite web|last=LibreTexts|first=Chemistry|date=29 August 2020|title=Stage II of Protein Catabolism|url=https://chem.libretexts.org/Courses/Eastern_Mennonite_University/EMU%3A_Chemistry_for_the_Life_Sciences_(Cessna)/20%3A_Energy_Metabolism/20.7%3A_Stage_II_of_Protein_Catabolism#:~:text=Oxidative%20Deamination,-In%20the%20breakdown&text=This%20reaction%20occurs%20primarily%20in%20liver%20mitochondria.&text=The%20amino%20group%20can%20then,the%20appropriate%20%CE%B1%2Dketo%20acids.|access-date=5 December 2020|website=Chemistry LibreTexts}}</ref> Oxidative deamination is stereospecific, meaning it contains different stereoisomers as reactants and products; this process is either catalyzed by L or D- amino acid oxidase and L-amino acid oxidase is present only in the liver and kidney.<ref>{{Cite book|last=Bhagavan & Ha|first=N.V.,Chung-Eun|title=Essentials Of Medical Biochemistry With Clinical Cases.|publisher=Elsevier|year=2015|isbn=9780124166974|location=USA|pages=231–233}}</ref> Oxidative deamination is an important step in the catabolism of amino acids, generating a more metabolizable form of the amino acid, and also generating [[Chemistry:Ammonia|ammonia]] as a toxic byproduct. The ammonia generated in this process can then be neutralized into [[Chemistry:Urea|urea]] via the [[Chemistry:Urea cycle|urea cycle]].

Much of the oxidative deamination occurring in cells involves the amino acid glutamate, which can be oxidatively deaminated by the enzyme [[Biology:Glutamate dehydrogenase|glutamate dehydrogenase]] (GDH), using [[Chemistry:Nicotinamide adenine dinucleotide|NAD]] or [[Chemistry:Nicotinamide adenine dinucleotide phosphate|NADP]] as a coenzyme. This reaction generates α-ketoglutarate (α-KG) and ammonia. Glutamate can then be regenerated from α-KG via the action of [[Biology:Transaminase|transaminase]]s or aminotransferase, which catalyze the transfer of an amino group from an amino acid to an α-keto acid. In this manner, an amino acid can transfer its amine group to glutamate, after which GDH can then liberate ammonia via oxidative deamination. This is a common pathway during amino acid catabolism.<ref>{{cite web|title=Amino Acid Catabolism: Nitrogen|url=https://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/amino.htm#glutdeam|website=Rensselaer Polytechnic Institute|access-date=20 June 2017|archive-url=https://web.archive.org/web/20170629094119/http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/amino.htm#glutdeam|archive-date=29 June 2017|url-status=dead}}</ref>

Another enzyme responsible for oxidative deamination is [[Biology:Monoamine oxidase|monoamine oxidase]], which catalyzes the deamination of monoamines via addition of oxygen. This generates the corresponding ketone- or aldehyde-containing form of the molecule, and generates ammonia. Monoamine oxidases MAO-A and MAO-B play vital roles in the degradation and inactivation of [[Biology:Monoamine neurotransmitter|monoamine neurotransmitter]]s such as [[Chemistry:Serotonin|serotonin]] and epinephrine.<ref name="pmid15279562">{{cite journal | vauthors = Edmondson DE, Mattevi A, Binda C, Li M, Hubálek F | title = Structure and mechanism of monoamine oxidase | journal = Current Medicinal Chemistry | volume = 11 | issue = 15 | pages = 1983–93 | date = August 2004 | pmid = 15279562 | doi = 10.2174/0929867043364784 }}</ref> Monoamine oxidases are important drug targets, targeted by [[Biology:Monoamine oxidase inhibitor|MAO inhibitors]] (MAOIs) such as [[Biology:Selegiline|selegiline]]. Glutamate dehydrogenase play an important role in oxidative deamination

==References==
{{reflist}}

==External links==
* [http://chemistry.elmhurst.edu/vchembook/632oxdeam.html Diagram from Elmhurst ]

[[Category:Metabolism]]



{{Sourceattribution|Oxidative deamination}}