Microinjected glutathione reductase crystals as indicators of the redox status in living cells

Item Type:	Article
Title:	Microinjected glutathione reductase crystals as indicators of the redox status in living cells
Creators Name:	Keese, M.A. and Saffrich, R. and Dandekar, T. and Becker, K. and Schirmer, R.H.
Abstract:	The flavoenzyme glutathione reductase catalyses electron transfer reactions between two major intracellular redox buffers, namely the NADPH/NADP+ couple and the 2 glutathione/glutathione disulfide couple. On this account, microcrystals of the enzyme were tested as redox probes of intracellular compartments. For introducing protein crystals into human fibroblasts, different methods (microinjection, particle bombardment and optical tweezers) were explored and compared. When glutathione reductase crystals are present in a cytosolic environment, the transition of the yellow E(ox) form to the orange-red 2-electron reduced charge transfer form, EH(2), is observed. Taking into account the midpoint potential of the E(ox)/EH(2) couple, the redox potential of the cytosol was found to be <−270 mV at pH 7.4 and 37°C. As a general conclusion, competent proteins in crystalline – that is signal-amplifying – form are promising probes for studying intracellular events.
Keywords:	Protein Crystal, Glutathione Reductase, Cytosol, Bilostic Crystal Transfer, Microinjection, Redox Potential
Source:	FEBS Letters
ISSN:	0014-5793
Publisher:	Elsevier
Volume:	447
Number:	2-3
Page Range:	135-138
Date:	26 March 1999
Official Publication:	https://doi.org/10.1016/S0014-5793(99)00296-3
PubMed:	View item in PubMed

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