Glyoxalase I (GloI) is a ubiquitous enzyme responsible for the primary defence against dicarbonyl glycation induced by methylglyoxal (MG), a toxic by-product of glycolysis and Calvin cycle. In plants, MG levels rise under various abiotic stresses, so GloI may play a crucial role in providing stress tolerance. GloI was demonstrated to localize in chloroplast, cytosol and nucleus. Moreover, a proteomic study suggested GloI existence also in mitochondria from potato tubers; nevertheless, so far, a mitochondrial GloI activity has never been measured. Here, for the first time GloI activity was assessed in highly purified mitochondria obtained from durum wheat (DWM). In particular, a high GloI activity was measured showing hyperbolic kinetics with Km and Vmax values equal to 225±15 μM and 0.134±0.002 U∙mg-1 of protein, respectively. Interestingly, an increase of GloI activity up to about 20% and 50% was obtained in DWM purified from salt- and osmotic-stressed seedlings, respectively, thus suggesting a key role of this enzyme in counteracting dicarbonyl glycation damage to DWM proteome. Identification of proteins target of dicarbonyl glycation in DWM merits further investigations.

First evidences of the existence of Glyoxalase I activity in durum wheat (Triticum durum Desf.) mitochondria and its activation under hyperosmotic stress conditions

Mario Soccio
;
D. Pastore
2018-01-01

Abstract

Glyoxalase I (GloI) is a ubiquitous enzyme responsible for the primary defence against dicarbonyl glycation induced by methylglyoxal (MG), a toxic by-product of glycolysis and Calvin cycle. In plants, MG levels rise under various abiotic stresses, so GloI may play a crucial role in providing stress tolerance. GloI was demonstrated to localize in chloroplast, cytosol and nucleus. Moreover, a proteomic study suggested GloI existence also in mitochondria from potato tubers; nevertheless, so far, a mitochondrial GloI activity has never been measured. Here, for the first time GloI activity was assessed in highly purified mitochondria obtained from durum wheat (DWM). In particular, a high GloI activity was measured showing hyperbolic kinetics with Km and Vmax values equal to 225±15 μM and 0.134±0.002 U∙mg-1 of protein, respectively. Interestingly, an increase of GloI activity up to about 20% and 50% was obtained in DWM purified from salt- and osmotic-stressed seedlings, respectively, thus suggesting a key role of this enzyme in counteracting dicarbonyl glycation damage to DWM proteome. Identification of proteins target of dicarbonyl glycation in DWM merits further investigations.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11369/372536
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