Deamination
(Redirected from Deaminating)
Deamination is a biochemical process that involves the removal of an amine group from a molecule. It plays a crucial role in the metabolism of amino acids and the production and elimination of waste nitrogen compounds in humans and other organisms.
In the broadest sense, deamination is the process wherein an amine group is detached from a molecule. This reaction is facilitated by enzymes known as deaminases.
Physiology of Deamination[edit | edit source]
In Humans[edit | edit source]
The human body primarily conducts deamination in the liver. An exception is the deamination of glutamate, which occurs in the kidneys. This process becomes pivotal when there's an overconsumption of protein. The amino acid's amino group is detached and converted into ammonia. The residual part of the amino acid, primarily composed of carbon and hydrogen, either gets recycled or oxidized to produce energy.
However, ammonia is toxic to humans, and the body has mechanisms to counteract its harmful effects. In the liver, through the urea cycle, ammonia gets transformed into urea or uric acid with the aid of carbon dioxide molecules. This transformation doesn't fall under deamination. The produced urea and uric acid are then harmlessly diffused into the bloodstream and eventually eliminated via urine.
Spontaneous Deamination[edit | edit source]
Spontaneous deamination can lead to the conversion of cytosine into uracil, releasing ammonia. This reaction can be artificially induced using bisulfite. Notably, bisulfite alters cytosine but leaves 5-methylcytosine untouched, providing a methodology for DNA sequencing to differentiate between methylated and non-methylated cytosine.
Within DNA, spontaneous deamination's repercussions are nullified by uracil-DNA glycosylase, which removes the "alien" uracil. This creates an abasic site, which is subsequently addressed and repaired by various enzymes and processes, ultimately restoring the correct cytosine. Base excision repair is one such pivotal repair mechanism.
Specific Deamination Reactions[edit | edit source]
5-methylcytosine[edit | edit source]
When 5-methylcytosine undergoes spontaneous deamination, it produces thymine. This is the predominant single nucleotide mutation. Enzymes like thymine-DNA glycosylase can rectify this prior to replication.
Guanine[edit | edit source]
Deamination transforms guanine into xanthine. Xanthine tends to pair with thymine, resulting in a mutation. Alkyladenine glycosylase (Aag) is involved in the corrective process during base excision repair.
Adenine[edit | edit source]
Adenine's deamination produces hypoxanthine, which selectively pairs with cytosine, leading to a mutation.
Additional Proteins Involved in Deamination[edit | edit source]
- APOBEC3G - Notably impacts HIV.
- Apolipoprotein B
See Also[edit | edit source]
References[edit | edit source]
Deamination Resources | |
---|---|
|
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
WikiMD's Wellness Encyclopedia |
Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD