Changes in enzymatic activities involved in glucose metabolism by acyl-CoAs in Trypanosoma cruzi.
This study describes the effect of some saturated and unsaturated free fatty acids and acyl-CoA thioesters on Trypanosoma cruzi glucose 6-phosphate dehydrogenase and hexokinase activities. Glucose 6-phosphate dehydrogenase was sensitive to the destabilizing effect provoked by free fatty acids, while hexokinase remained unaltered. Glucose 6-phosphate dehydrogenase inhibition by free fatty acids was dependent on acid concentration and chain length. Both enzymes were inhibited when they were incubated with acyl-CoA thioesters. The acyl-CoA thioesters inhibited glucose 6-phosphate dehydrogenase at a lower concentration than the free fatty acids; the ligands glucose 6-phosphate and NADP+ afforded protection. The inhibition of hexokinase by acyl-CoAs was not reverted when the enzyme was incubated with ATP. The type of inhibition found with acyl-CoAs in relation to glucose 6-phosphate dehydrogenase and hexokinase suggests that this type inhibition may produce an in vivo modulation of these enzymatic activities.
García de Lema
M
M
Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800-Río Cuarto, Córdoba, Argentina.
Lucchesi
G
G
Racagni
G
G
Machado-Domenech
E E
EE
D000214:Acyl Coenzyme A / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D019298:Glucose-6-Phosphate / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D006593:Hexokinase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D009249:NADP / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism
D000214:Acyl Coenzyme A; D004791:Enzyme Inhibitors; D005230:Fatty Acids, Nonesterified; D005231:Fatty Acids, Unsaturated; D009249:NADP; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate; D005954:Glucosephosphate Dehydrogenase; D006593:Hexokinase