Alpha-ketoglutarate, a key molecule involved in nitrogen circulation in both animals and plants, in the context of human gut microbiota and protein metabolism
(2022) In Advances in Medical Sciences 67(1). p.142-147- Abstract
Purpose: Nitrogen (N2) is an indispensable metabolite required for the synthesis of protein. In animals, gut bacteria and, to a certain extent, even hepatocytes, are able to assimilate nitrogen from ammonium (NH4+), which is essentially derived from the amine group (-NH2) and which is at the same time a very toxic metabolite. Initially, NH4+ is coupled to alpha-ketoglutarate (AKG), a reaction which results in the appearance of glutamate (one amine group), and after that, in the appearance of glutamine - containing two amine groups. The surplus of NH4+ which is not utilized by AKG/glutamate/glutamine is eliminated as urea in the urine, via the urea... (More)
Purpose: Nitrogen (N2) is an indispensable metabolite required for the synthesis of protein. In animals, gut bacteria and, to a certain extent, even hepatocytes, are able to assimilate nitrogen from ammonium (NH4+), which is essentially derived from the amine group (-NH2) and which is at the same time a very toxic metabolite. Initially, NH4+ is coupled to alpha-ketoglutarate (AKG), a reaction which results in the appearance of glutamate (one amine group), and after that, in the appearance of glutamine - containing two amine groups. The surplus of NH4+ which is not utilized by AKG/glutamate/glutamine is eliminated as urea in the urine, via the urea cycle in hepatocytes. Plants bacteria also assimilate nitrogen from NH4+, by its fixation to ammonia (NH3)/NH4+. Materials/methods: Previous studies have shown that AKG (also known as 2-oxo-glutaric acid or 2-oxopentanedioic acid), the primary metabolite of Rhizobium and gut bacteria, is essential for the assimilation of nitrogen. Results: Symbiotic bacteria produce AKG, which together with glutamate dehydrogenase (GDH), ‘generates’ primarily amine groups from NH4+. The final product is glutamate – the first amino acid. Glutamate has the capacity to be converted to glutamine, through the action of glutamine synthetase, after the assimilation of the second nitrogen from NH4+. Conclusion: Glutamate/glutamine, derivatives of AKG metabolism, are capable of donating amine groups for the creation of other amino acids, following NH2 transamination to certain metabolites e.g., short chain fatty acids (SCFA).
(Less)
- author
- Pierzynowski, Stefan LU and Pierzynowska, Kateryna LU
- organization
- publishing date
- 2022-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Amino acids, E. coli, Gastrointestinal tract, Nitrogen fixation, Rhizobium
- in
- Advances in Medical Sciences
- volume
- 67
- issue
- 1
- pages
- 6 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85125483120
- pmid:35245838
- ISSN
- 1896-1126
- DOI
- 10.1016/j.advms.2022.02.004
- language
- English
- LU publication?
- yes
- id
- a3b41e7f-4d6d-46e1-b68a-4d4ee954311b
- date added to LUP
- 2022-04-14 11:04:46
- date last changed
- 2024-04-10 18:22:35
@article{a3b41e7f-4d6d-46e1-b68a-4d4ee954311b, abstract = {{<p>Purpose: Nitrogen (N<sub>2</sub>) is an indispensable metabolite required for the synthesis of protein. In animals, gut bacteria and, to a certain extent, even hepatocytes, are able to assimilate nitrogen from ammonium (NH<sub>4</sub><sup>+</sup>), which is essentially derived from the amine group (-NH<sub>2</sub>) and which is at the same time a very toxic metabolite. Initially, NH<sub>4</sub><sup>+</sup> is coupled to alpha-ketoglutarate (AKG), a reaction which results in the appearance of glutamate (one amine group), and after that, in the appearance of glutamine - containing two amine groups. The surplus of NH<sub>4</sub><sup>+</sup> which is not utilized by AKG/glutamate/glutamine is eliminated as urea in the urine, via the urea cycle in hepatocytes. Plants bacteria also assimilate nitrogen from NH<sub>4</sub><sup>+</sup>, by its fixation to ammonia (NH<sub>3</sub>)/NH<sub>4</sub><sup>+</sup>. Materials/methods: Previous studies have shown that AKG (also known as 2-oxo-glutaric acid or 2-oxopentanedioic acid), the primary metabolite of Rhizobium and gut bacteria, is essential for the assimilation of nitrogen. Results: Symbiotic bacteria produce AKG, which together with glutamate dehydrogenase (GDH), ‘generates’ primarily amine groups from NH<sub>4</sub><sup>+</sup>. The final product is glutamate – the first amino acid. Glutamate has the capacity to be converted to glutamine, through the action of glutamine synthetase, after the assimilation of the second nitrogen from NH<sub>4</sub><sup>+</sup>. Conclusion: Glutamate/glutamine, derivatives of AKG metabolism, are capable of donating amine groups for the creation of other amino acids, following NH<sub>2</sub> transamination to certain metabolites e.g., short chain fatty acids (SCFA).</p>}}, author = {{Pierzynowski, Stefan and Pierzynowska, Kateryna}}, issn = {{1896-1126}}, keywords = {{Amino acids; E. coli; Gastrointestinal tract; Nitrogen fixation; Rhizobium}}, language = {{eng}}, number = {{1}}, pages = {{142--147}}, publisher = {{Elsevier}}, series = {{Advances in Medical Sciences}}, title = {{Alpha-ketoglutarate, a key molecule involved in nitrogen circulation in both animals and plants, in the context of human gut microbiota and protein metabolism}}, url = {{http://dx.doi.org/10.1016/j.advms.2022.02.004}}, doi = {{10.1016/j.advms.2022.02.004}}, volume = {{67}}, year = {{2022}}, }