Pande S V, Lee T S, Murthy M S
Clinical Research Institute of Montreal, Laboratory of Intermediary Metabolism, Quebec, Canada.
Biochem Int. 1988 Dec;17(6):1021-8.
The carnitine palmitoyltransferase (CPT) activities of the outer and the inner membranes of rat liver mitochondria were markedly activated by increase in the ionic strength of the assay medium. ATP at physiological concentrations in the presence of Mg2+ effectively reversed the above effect with octanoyl-CoA, but not with palmitoyl-CoA, as a substrate. Other nucleotides were unable to substitute for ATP. This ATP-Mg2+ effect on the CPT activity was not seen with mitochondria of heart or of skeletal muscles. The remarkable nucleotide, substrate and tissue specificity of these effects indicate that the above phenomenon may be functional in vivo to regulate the ability of liver mitochondria to utilize medium chain fatty acids via the carnitine-dependent route.
大鼠肝脏线粒体的外膜和内膜的肉碱棕榈酰转移酶（CPT）活性会因检测介质离子强度的增加而显著激活。在存在Mg2+的生理浓度下，ATP能有效逆转上述以辛酰辅酶A为底物时的作用，但以棕榈酰辅酶A为底物时则不能。其他核苷酸无法替代ATP。心脏或骨骼肌线粒体未观察到这种ATP-Mg2+对CPT活性的影响。这些作用显著的核苷酸、底物和组织特异性表明，上述现象可能在体内发挥作用，以调节肝脏线粒体通过肉碱依赖性途径利用中链脂肪酸的能力。
