Conferral of malonyl coenzyme A sensitivity to purified rat heart mitochondrial carnitine palmitoyltransferase.
An immunoaffinity column against the 86-kDa malonyl-CoA-binding protein of beef heart mitochondria was prepared, and the properties of the eluates were compared to those of eluates of an anti-carnitine palmitoyltransferase immunoaffinity column. Both eluates contain seven to eight major proteins with a malonyl-CoA-binding capacity of approximately 5 nmol/mg of protein; in contrast, the eluates from a preimmune IgG column did not contain any of the major proteins. The eluates from both immunoaffinity columns conferred malonyl-CoA sensitivity to purified rat heart mitochondrial carnitine palmitoyltransferase (CPTi/CPT-II). Addition of phospholipids increased the degree of malonyl-CoA inhibition. Doubling the amount of column eluate approximately doubled the malonyl-CoA sensitivity when added to a fixed amount of CPT; i.e., the inhibition increased from 32 to 67%. These results show that CPTi/CPT-II is capable of exhibiting malonyl-CoA sensitivity in the presence of malonyl-CoA-binding proteins. The results do not support the concept that the 86-kDa malonyl-CoA-binding protein is detergent-inactivated carnitine palmitoyltransferase I;rather, they suggest that it is a regulatory subunit of a carnitine palmitoyltransferase complex.
Chung
C H
CH
Department of Biochemistry, Michigan State University, East Lansing 48824.
Woldegiorgis
G
G
Dai
G
G
Shrago
E
E
Bieber
L L
LL
D000818:Animals; D015153:Blotting, Western; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002417:Cattle; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D008316:Malonyl Coenzyme A / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000201:enzymology*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000378:metabolism
D010743:Phospholipids; D012710:Serum Albumin, Bovine; D008316:Malonyl Coenzyme A; D002334:Carnitine O-Palmitoyltransferase