Metal catalyzed lens crystallin oxidation during aging and in diabetes: The role of glutathione

Xingjun Fan, J. Zhang, I. Nemet, V. M. Monnier

Research output: Contribution to conferencePaper

Abstract

In summary, the data presented in this study suggest metal catalyzed oxidation of lysines occurs in the aging human lens, most likely by the Suyama mechanism involving Cu2+, methylglyoxal whereby H2O 2 most likely originates from ascorbic acid oxidation. The conversion of allysine to 2-aminoadipic acid does not readily occur in the lens due to the anaerobic environment. Thus, if high levels of 2-AAA are detected, this implicates a functional drop of glutathione and decreased ability to detoxify H202. Therefore 2-AAA is expected to accumulate during nuclear sclerosis together with the formation of protein-protein and protein-GSH disulfides. The findings strongly implicate dicarbonyl/metal catalyzed oxidation of lysine to allysine, whereby low GSH combined with ascorbate-derived H2O2 likely contributes toward 2-AAA formation, since virtually no 2-AAA formed in presence of methylglyoxal instead of ascorbate. An important translational conclusion is that chelating agents might help delay nuclear sclerosis, and that glutathione plays a key role in preventing oxidation of protein carbonyls.

Original languageEnglish (US)
Pages92-100
Number of pages9
StatePublished - Jan 1 2010
Externally publishedYes
Event2009 International Symposium on the Maillard Reaction - Palm Cove, QLD, Australia
Duration: Aug 29 2009Aug 31 2009

Other

Other2009 International Symposium on the Maillard Reaction
CountryAustralia
CityPalm Cove, QLD
Period8/29/098/31/09

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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