用棕榈酰辅酶A和辛酰辅酶A测定大鼠肝脏和心脏中的肉碱酰基转移酶活性。潜伏性、钾离子、二价金属离子和丙二酰辅酶A的影响。

Carnitine acyltransferase activities in rat liver and heart measured with palmitoyl-CoA and octanoyl-CoA. Latency, effects of K+, bivalent metal ions and malonyl-CoA.

作者信息

Saggerson E D

出版信息

Biochem J. 1982 Feb 15;202(2):397-405. doi: 10.1042/bj2020397.

DOI:10.1042/bj2020397

PMID:7092822

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1158124/

Abstract

Liver carnitine acyltransferase activities with palmitoyl-CoA and octanoyl-CoA as substrates and heart carnitine palmitoyltransferase were measured as overt activities in whole mitochondria or in mitochondria disrupted by sonication or detergent treatment. All measurements were made in sucrose/KCl-based media of 300 mosmol/litre. 2. In liver mitochondria, acyltransferase measured with octanoyl-CoA, like carnitine palmitoyltransferase, was found to have latent and overt activities. 3. Liver acyltransferase activities measured with octanoyl-CoA and palmitoyl-CoA differed in their response to changes in [K+], Triton X-100 treatment and, in particular, in their response to Mg2+. Mg2+ stimulated activity with octanoyl-CoA, but inhibited carnitine palmitoyltransferase. 4. The effects of K+ and Mg2+ on liver overt carnitine palmitoyltransferase activity were abolished by Triton X-100 treatment. 5. Heart overt carnitine palmitoyltransferase activity differed from the corresponding activity in liver in that it was more sensitive to changes in [K+] and was stimulated by Mg2+. Heart had less latent carnitine palmitoyltransferase activity than did liver. 6. Overt carnitine palmitoyltransferase in heart mitochondria was extremely sensitive to inhibition by malonyl-CoA. Triton X-100 abolished the effect of low concentrations of malonyl-CoA on this activity. 7. The inhibitory effect of malonyl-CoA on heart carnitine palmitoyltransferase could be overcome by increasing the concentration of palmitoyl-CoA.

摘要

以棕榈酰辅酶A和辛酰辅酶A为底物的肝脏肉碱酰基转移酶活性以及心脏肉碱棕榈酰转移酶活性，在完整线粒体中或经超声处理或去污剂处理破坏的线粒体中，作为明显活性进行测定。所有测定均在300毫渗摩尔/升的蔗糖/氯化钾基介质中进行。2. 在肝脏线粒体中，以辛酰辅酶A测定的酰基转移酶，与肉碱棕榈酰转移酶一样，具有潜在活性和明显活性。3. 以辛酰辅酶A和棕榈酰辅酶A测定的肝脏酰基转移酶活性，在对[K⁺]变化、Triton X - 100处理的反应上有所不同，特别是在对Mg²⁺的反应上。Mg²⁺刺激以辛酰辅酶A为底物的活性，但抑制肉碱棕榈酰转移酶。4. Triton X - 100处理消除了K⁺和Mg²⁺对肝脏明显肉碱棕榈酰转移酶活性的影响。5. 心脏明显肉碱棕榈酰转移酶活性与肝脏中的相应活性不同，在于它对[K⁺]变化更敏感，且受Mg²⁺刺激。心脏的潜在肉碱棕榈酰转移酶活性比肝脏少。6. 心脏线粒体中的明显肉碱棕榈酰转移酶对丙二酰辅酶A的抑制极为敏感。Triton X - 100消除了低浓度丙二酰辅酶A对该活性的影响。7. 增加棕榈酰辅酶A的浓度可克服丙二酰辅酶A对心脏肉碱棕榈酰转移酶的抑制作用。