On the mechanism of glycolysis stimulation by mitochondria from Guérin epithelioma.
The experiments were performed to determine the factor(s) responsible for the stimulatory effect on glycolysis in the cytosol (post-microsomal supernatant) of mitochondria isolated from Guérin epithelioma. It was found that epithelioma mitochondria contain bound hexokinase which constitutes about 50% of the total cellular hexokinase activity. The solubilized and partially purified enzyme, when added to the cytosol, stimulated glycolysis. The stimulatory effect of mitochondria on glycolysis was associated with the decrease of adenylate energy charge which was caused by an apparently very fast production of ADP in the hexokinase reaction. A large part of ATP hydrolyzed in this process was converted to IMP and NH3, which can additionally stimulate glycolysis through its stimulatory effect on phosphofructokinase. It is therefore suggested that the stimulatory effect of epithelioma mitochondria on glycolysis can be explained by production of ADP by the hexokinase associated with these mitochondria.
Tomasiak
M
M
Department of Biochemistry, Medical Academy, Białystok, Poland.
Rzeczycki
W
W
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000641:Ammonia / Q000494:pharmacology; D000818:Animals; D002277:Carcinoma / Q000648:ultrastructure*; D005260:Female; D006019:Glycolysis / Q000187:drug effects*; D006593:Hexokinase / Q000378:metabolism; D007291:Inosine Monophosphate / Q000494:pharmacology; D008297:Male; D008928:Mitochondria / Q000201:enzymology / Q000502:physiology; D009374:Neoplasms, Experimental / Q000648:ultrastructure; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D014020:Tissue Extracts / Q000494:pharmacology*
D014020:Tissue Extracts; D007291:Inosine Monophosphate; D000244:Adenosine Diphosphate; D000641:Ammonia; D000255:Adenosine Triphosphate; D006593:Hexokinase