Glycyl-methionine or Gly-Met is a dipeptide consisting of the amino acids glycine and methionine.[1] It plays a role as a metabolite. It is reverse of Methionylglycine or Met-Gly sequence.
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Names | |
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IUPAC name
L-Glycyl-L-methionine
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Other names
(2S)-2-[(2-aminoacetyl)amino]-4-methylsulfanylbutanoic acid
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Identifiers | |
3D model (JSmol)
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Abbreviations | gly-met |
ChEBI |
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ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.008.252 |
EC Number |
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PubChem CID
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UNII | |
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Properties | |
C7H14N2O3S | |
Molar mass | 206.26 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Oxidation
editThe oxidation of Gly-Met and its reverse sequence, Met-Gly, has differences. Both photooxidation and collision-induced dissociation of Gly-Met happen through electron transfer from either the sulfur atom or the terminal amino group when it is in its uncharged state. This process leads to the formation of α-protons and sulfur-centered cation radicals in Gly-Met.[2]
However, the photooxidation of Met-Gly behaves differently from Gly-Met. The peptide’s conformation plays a crucial role in understanding the oxidation mechanism. In Met-Gly, the process leads to the formation of an open-chain sulfur-centered cation radical. This radical then releases a proton from the N-terminal amino group, resulting in a five-membered cyclic radical structure with a three-electron bond between the sulfur and nitrogen atoms.
Peptides can adopt different conformations—cationic, zwitterionic, or anionic—depending on the solvent and pH. The zwitterionic form of Gly-Met is particularly important as it is responsible for the formation of sulfur-centered radicals.[3] This same mechanism can cause similar damage in proteins.
References
edit- ^ "L-Glycylmethionine". PubChem.
- ^ Lau, Justin Kai-Chi; Lo, Seydina; Zhao, Junfang; Siu, K W Michael; Hopkinson, Alan C. (April 2013). "Fragmentation chemistry of [Met-Gly]•+, [Gly-Met]•+, and [Met-Met]•+ radical cations". Journal of the American Society for Mass Spectrometry. 24 (4): 543–553. doi:10.1007/s13361-013-0581-5. PMID 23440718.
- ^ Babu, Sainath; Fronczek, Frank R.; Uppu, Rao M.; Claville, Michelle O. (July 2024). "Crystal structures of the isomeric dipeptides L-glycyl-L-methionine and L-methionyl-L-glycine". Acta Crystallographica Section E: Crystallographic Communications. 80 (7). Part 7. doi:10.1107/S2056989024005504. PMC 11223706.