TY - JOUR
T1 - Kinetic characteristics of rat liver peroxisomal nafenopin-CoA ligase
AU - Roberts, Benjamin J.
AU - Macleod, John K.
AU - Singh, Inderjit
AU - Knights, Kathleen M.
PY - 1995/5/11
Y1 - 1995/5/11
N2 - In this study we have demonstrated that rat hepatic peroxisomes catalyse the formation of nafenopin-CoA. The process is mediated by apparent high affinity (Km 6.7 μM), low capacity (Vmax 0.31 nmol/mg/min) and low affinity, high capacity isoforms. Palmitic acid (Ki 1.1 μM), r(-) ibuprofen (Ki 7.9 μM), ciprofibrate (Ki 60.2 μM) and clofibric acid (Ki 86.8 μM) competitively inhibited nafenopin-CoA formation catalysed by the apparent high affinity isoform. An antibody raised against the microsomal palmitoyl-CoA ligase inhibited the equivalent peroxisomal enzyme significantly (P < 0.001) but did not inhibit peroxisomal nafenopin-CoA ligase activity. These data suggest that nafenopin-CoA formation is catalysed by a peroxisomal CoA ligase which differs from the peroxisomal long chain fatty acid-CoA ligase in relation to its xenobiotic/antibody inhibitor profile and kinetic characteristics.
AB - In this study we have demonstrated that rat hepatic peroxisomes catalyse the formation of nafenopin-CoA. The process is mediated by apparent high affinity (Km 6.7 μM), low capacity (Vmax 0.31 nmol/mg/min) and low affinity, high capacity isoforms. Palmitic acid (Ki 1.1 μM), r(-) ibuprofen (Ki 7.9 μM), ciprofibrate (Ki 60.2 μM) and clofibric acid (Ki 86.8 μM) competitively inhibited nafenopin-CoA formation catalysed by the apparent high affinity isoform. An antibody raised against the microsomal palmitoyl-CoA ligase inhibited the equivalent peroxisomal enzyme significantly (P < 0.001) but did not inhibit peroxisomal nafenopin-CoA ligase activity. These data suggest that nafenopin-CoA formation is catalysed by a peroxisomal CoA ligase which differs from the peroxisomal long chain fatty acid-CoA ligase in relation to its xenobiotic/antibody inhibitor profile and kinetic characteristics.
KW - hepatic peroxisomes
KW - nafenopin
KW - nafenopin-CoA ligase
KW - palmitic acid, long chain fatty acid-CoA ligase
KW - xenobiotic carboxylic acids
UR - http://www.scopus.com/inward/record.url?scp=0029045105&partnerID=8YFLogxK
U2 - 10.1016/0006-2952(94)00516-O
DO - 10.1016/0006-2952(94)00516-O
M3 - Article
C2 - 7763316
AN - SCOPUS:0029045105
VL - 49
SP - 1335
EP - 1339
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
SN - 0006-2952
IS - 9
ER -