Reciprocal enzymatic interference of carnitine palmitoyltransferase I and glycerol-3-phosphate acyltransferase in purified liver mitochondria.
(i) Highly purified mitochondrial fractions were practically devoid of microsomal contamination and of acyl-CoA ligase activity. (ii) In mitochondria, glycerol-3-phosphate acyltransferase (GPAT) activity was supported by two enzymes, the first being very active at low palmitoyl-CoA/albumin ratios and sensitive to external agents (external form), the second being detected only at higher palmitoyl-CoA/albumin ratios and insensitive to external agents (internal form). (iii) Carnitine palmitoyltransferase I (CPT I) activity was shown to inhibit external GPAT activity only. (iv) Glycerol-3-phosphate exerted an inhibitory effect on CPT I, even when GPAT was inactive. Reciprocal interaction of CPT I and GPAT was discussed with regard to the balance existing between fatty acid oxidation and esterification metabolic pathways.
Beauseigneur
F
F
UPRES Lipides et Nutrition, EA 2422 Université de Bourgogne, Dijon, France.
Tsoko
M
M
Gresti
J
J
Clouet
P
P
D000818:Animals; D015415:Biomarkers; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D003066:Coenzyme A Ligases / Q000032:analysis; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism*; D006706:Homeostasis; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology / Q000648:ultrastructure; D008930:Mitochondria, Liver / Q000201:enzymology* / Q000648:ultrastructure; D008995:Monoamine Oxidase / Q000032:analysis; D011205:Povidone; D051381:Rats; D017208:Rats, Wistar; D012822:Silicon Dioxide
D015415:Biomarkers; C016039:Percoll; D012822:Silicon Dioxide; D008995:Monoamine Oxidase; D005992:Glycerol-3-Phosphate O-Acyltransferase; D002334:Carnitine O-Palmitoyltransferase; D003066:Coenzyme A Ligases; D011205:Povidone