Smith 2012 Biochem J: Difference between revisions
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{{Publication | {{Publication | ||
|title=Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP (2012) Identification of a novel malonyl-CoA IC50 for CPT-I: implications for predicting ''in vivo'' fatty acid oxidation rates. Biochem J 448: 13-20. ย | |title=Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP (2012) Identification of a novel malonyl-CoA IC50 for CPT-I: implications for predicting ''in vivo'' fatty acid oxidation rates. Biochem J 448: 13-20. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/22928974 PMID: 22928974] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/22928974 PMID: 22928974] | ||
|authors=Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP | |authors=Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP | ||
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|journal=Biochem J | |journal=Biochem J | ||
|abstract=Published values regarding the sensitivity (IC50) of CPT-I (carnitine palmitoyltransferase I) to M-CoA (malonyl-CoA) inhibition in isolated mitochondria are inconsistent with predicted ''in vivo'' rates of fatty acid oxidation. Therefore we have re-examined M-CoA inhibition kinetics under various P-CoA (palmitoyl-CoA) concentrations in both isolated mitochondria and PMFs (permeabilized muscle fibres). PMFs have an 18-fold higher IC50 (0.61 compared with 0.034 ฮผM) in the presence of 25 ฮผM P-CoA and a 13-fold higher IC50 (6.3 compared with 0.49 ฮผM) in the presence of 150 ฮผM P-CoA compared with isolated mitochondria. M-CoA inhibition kinetics determined in PMFs predicts that CPT-I activity is inhibited by 33% in resting muscle compared with >95% in isolated mitochondria. Additionally, the ability of M-CoA to inhibit CPT-I appears to be dependent on P-CoA concentration, as the relative inhibitory capacity of M-CoA is decreased with increasing P-CoA concentrations. Altogether, the use of PMFs appears to provide an M-CoA IC50 that better reflects the predicted in vivo rates of fatty acid oxidation. These findings also demonstrate that the ratio of [P-CoA]/[M-CoA] is critical for regulating CPT-I activity and may partially rectify the ''in vivo'' disconnect between M-CoA content and CPT-I flux within the context of exercise and Type 2 diabetes. | |abstract=Published values regarding the sensitivity (IC50) of CPT-I (carnitine palmitoyltransferase I) to M-CoA (malonyl-CoA) inhibition in isolated mitochondria are inconsistent with predicted ''in vivo'' rates of fatty acid oxidation. Therefore we have re-examined M-CoA inhibition kinetics under various P-CoA (palmitoyl-CoA) concentrations in both isolated mitochondria and PMFs (permeabilized muscle fibres). PMFs have an 18-fold higher IC50 (0.61 compared with 0.034 ฮผM) in the presence of 25 ฮผM P-CoA and a 13-fold higher IC50 (6.3 compared with 0.49 ฮผM) in the presence of 150 ฮผM P-CoA compared with isolated mitochondria. M-CoA inhibition kinetics determined in PMFs predicts that CPT-I activity is inhibited by 33% in resting muscle compared with >95% in isolated mitochondria. Additionally, the ability of M-CoA to inhibit CPT-I appears to be dependent on P-CoA concentration, as the relative inhibitory capacity of M-CoA is decreased with increasing P-CoA concentrations. Altogether, the use of PMFs appears to provide an M-CoA IC50 that better reflects the predicted in vivo rates of fatty acid oxidation. These findings also demonstrate that the ratio of [P-CoA]/[M-CoA] is critical for regulating CPT-I activity and may partially rectify the ''in vivo'' disconnect between M-CoA content and CPT-I flux within the context of exercise and Type 2 diabetes. | ||
|keywords=Type 2 diabetes, ย | |keywords=Type 2 diabetes, | ||
|mipnetlab=CA Guelph Holloway GP | |||
}} | }} | ||
{{Labeling | {{Labeling | ||
Revision as of 15:21, 14 November 2012
| Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP (2012) Identification of a novel malonyl-CoA IC50 for CPT-I: implications for predicting in vivo fatty acid oxidation rates. Biochem J 448: 13-20. |
Smith BK, Perry CG, Koves TR, Wright DC, Smith JC, Neufer PD, Muoio DM, Holloway GP (2012) Biochem J
Abstract: Published values regarding the sensitivity (IC50) of CPT-I (carnitine palmitoyltransferase I) to M-CoA (malonyl-CoA) inhibition in isolated mitochondria are inconsistent with predicted in vivo rates of fatty acid oxidation. Therefore we have re-examined M-CoA inhibition kinetics under various P-CoA (palmitoyl-CoA) concentrations in both isolated mitochondria and PMFs (permeabilized muscle fibres). PMFs have an 18-fold higher IC50 (0.61 compared with 0.034 ฮผM) in the presence of 25 ฮผM P-CoA and a 13-fold higher IC50 (6.3 compared with 0.49 ฮผM) in the presence of 150 ฮผM P-CoA compared with isolated mitochondria. M-CoA inhibition kinetics determined in PMFs predicts that CPT-I activity is inhibited by 33% in resting muscle compared with >95% in isolated mitochondria. Additionally, the ability of M-CoA to inhibit CPT-I appears to be dependent on P-CoA concentration, as the relative inhibitory capacity of M-CoA is decreased with increasing P-CoA concentrations. Altogether, the use of PMFs appears to provide an M-CoA IC50 that better reflects the predicted in vivo rates of fatty acid oxidation. These findings also demonstrate that the ratio of [P-CoA]/[M-CoA] is critical for regulating CPT-I activity and may partially rectify the in vivo disconnect between M-CoA content and CPT-I flux within the context of exercise and Type 2 diabetes. โข Keywords: Type 2 diabetes
โข O2k-Network Lab: CA Guelph Holloway GP
Labels:
Organism: Rat
Preparation: Permeabilized tissue, Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.
Regulation: Fatty Acid"Fatty Acid" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property. Coupling state: LEAK, OXPHOS
HRR: Oxygraph-2k
