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 conferencePaperpeer-review

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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