Homocysteine thiolactone

Homocysteine thiolactone (HTL) is an intramolecular thioester of homocysteine synthesized by methionyl-tRNA synthetase in an error-editing reaction that prevents translational incorporation of homocysteine into proteins. It can damage proteins through homocysteinylation of protein lysine residues.[1] HTL has been reported to form isopeptide bonds with lysine residues in substrate proteins, a post-translational modification known as N-homocysteinylation (N-hcy). This causes protein damage via a thiyl radical mechanism.

Homocysteine thiolactone
Names
IUPAC name
(3S)-3-aminothiolan-2-one
Identifiers
3D model (JSmol)
80591
ChEBI
ChEMBL
ChemSpider
  • InChI=1S/C4H7NOS/c5-3-1-2-7-4(3)6/h3H,1-2,5H2/t3-/m0/s1
    Key: KIWQWJKWBHZMDT-VKHMYHEASA-N
  • C1CSC(=O)[C@H]1N
Properties
C4H7NOS
Molar mass 117.17 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

When N-hcy hits α-syn, it exacerbates α-syn aggregation, neurotoxicity, and dopaminergic neuronal degeneration. It also damages the protein DJ-1, contributing to Parkinson's disease.[2]

References

edit
  1. ^ Jakubowski, Hieronim (February 2000). "Homocysteine Thiolactone: Metabolic Origin and Protein Homocysteinylation in Humans". The Journal of Nutrition. 130 (2): 377S–381S. doi:10.1093/jn/130.2.377S. PMID 10721911.
  2. ^ Guo, Tao; Zhou, Lingyan; Xiong, Min; Xiong, Jing; Huang, Juan; Li, Yiming; Zhang, Guoxin; Chen, Guiqin; Wang, Zhi-Hao; Xiao, Tingting; Hu, Dan; Bao, Anyu; Zhang, Zhentao (May 2024). "N-homocysteinylation of DJ-1 promotes neurodegeneration in Parkinson's disease". Aging Cell. 23 (5): e14124. doi:10.1111/acel.14124. PMC 11113254. PMID 38380563.