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Licensed Unlicensed Requires Authentication Published by De Gruyter June 1, 2005

Homocysteine-Thiolactone and S-Nitroso-Homocysteine Mediate Incorporation of Homocysteine into Protein in Humans

  • Hieronim Jakubowski
From the journal


Indirect pathways, involving homocysteine (Hcy)-thiolactone and S-nitroso-Hcy, allow incorporation of Hcy into protein. Hcy-thiolactone, synthesized by methionyl-tRNA synthetase in all organisms investigated, including human, modifies proteins post-translationally by forming adducts in which Hcy is linked by amide bonds to e-amino group of protein lysine residues. SNitroso-Hcy, synthesized in human vascular endothelial cells, is incorporated translationally into peptide bonds in protein at positions normally occupied by methionine. Hcy-N-hemoglobin and Hcy-N-albumin constitute a major pool of Hcy in human blood. Hcy-thiolactone is present in human plasma. Modification with Hcy-thiolactone leads to protein damage. Hcy-thiolactone is detoxified by Hcy-thiolactonase/paraoxonase present in a subset of high-density lipoprotein particles in humans.

Published Online: 2005-06-01
Published in Print: 2003-11-17

Copyright © 2003 by Walter de Gruyter GmbH & Co. KG

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