Hall M, Saggerson E D
Biochem J. 1985 Feb 15;226(1):275-82. doi: 10.1042/bj2260275.
Incubation of rat adipocytes with the same range of noradrenaline concentrations that stimulate lipolysis caused a rapid and stable decrease in the activity of fatty acyl-CoA synthetase. Corticotropin, glucagon and dibutyryl cyclic AMP also decreased the activity of the enzyme. The effect of noradrenaline was apparent over a wide range of concentrations for the three substrates of the enzyme. A novel fluorescence assay of fatty acyl-CoA synthetase using (1,N6-etheno)-CoA is described. The effect of noradrenaline was not abolished by inclusion of albumin in homogenization buffers, persisted through subcellular fractionation and isolation of microsomes (microsomal fractions) and even survived treatment of microsomes with Triton X-100. The effect of noradrenaline was rapidly reversed within cells by the subsequent addition of insulin or propranolol. The inclusion of fluoride in homogenization buffers did not alter the observed effect of noradrenaline. Additions of cyclic AMP-dependent protein kinase to adipocyte microsomes caused considerable phosphorylation of microsomal protein by [gamma-32P]ATP, but did not affect the activity of fatty acyl-CoA synthetase.
用能刺激脂肪分解的相同范围去甲肾上腺素浓度孵育大鼠脂肪细胞，会导致脂肪酰基辅酶A合成酶活性迅速且稳定地下降。促肾上腺皮质激素、胰高血糖素和二丁酰环磷酸腺苷也会降低该酶的活性。去甲肾上腺素对该酶的三种底物在很宽的浓度范围内都有明显作用。本文描述了一种使用(1,N6-乙烯基)-辅酶A对脂肪酰基辅酶A合成酶进行的新型荧光测定法。在匀浆缓冲液中加入白蛋白并不能消除去甲肾上腺素的作用，该作用在亚细胞分级分离和微粒体（微粒体部分）分离过程中持续存在，甚至在用 Triton X-100处理微粒体后仍存在。随后加入胰岛素或普萘洛尔可使细胞内去甲肾上腺素的作用迅速逆转。在匀浆缓冲液中加入氟化物不会改变所观察到的去甲肾上腺素的作用。向脂肪细胞微粒体中添加环磷酸腺苷依赖性蛋白激酶会导致微粒体蛋白被[γ-32P]ATP大量磷酸化，但不影响脂肪酰基辅酶A合成酶的活性。
