Journal article

DECAY OF HEXOKINASE DURING RETICULOCYTE MATURATION - IS OXIDATIVE DAMAGE A SIGNAL FOR DESTRUCTION

DR THORBURN, E BEUTLER

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS | Published : 1989

Abstract

Proteolysis of hexokinase in cell-free systems prepared from rabbit reticulocytes has been shown previously to be ATP-dependent and apparently mediated by the ubiquitin system (Magnani et al. J. Biol.Chem.261, 8327-8333). We have investigated this phenomenon, but found no substantial loss of hexokinase in cell-free systems prepared from fresh lysates. Storage of lysates at -20 degrees C or addition of a free radical generating system was required to demonstrate rapid ATP-dependent decay. It appears that initial oxidative damage to hexokinase does not abolish its activity but allows it to be recognized by an ATP-dependent proteolytic system. The relevance of this mechanism to in vivo degradat..

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