Kawashima Y, Suzuki Y, Hashimoto Y
Lipids. 1977 May;12(5):434-7. doi: 10.1007/BF02533628.
The rate of chain elongation of palmityl-CoA to stearyl-CoA in rat liver microsomes was studied in connection with the nutritional status of the rats. The microsomal chain elongation activity, which had been decreased by starvation for 48 hr, was rapidly increased to a high level on refeeding. The apparent Km value for malonyl-CoA in both normal and refed rats was the same, 1.2 X 10(4)M. Both cycloheximide and actinomycin D prevented the induction of microsomal chain elongation activity which was associated with refeeding. In addition, the activity of acyl-CoA hydrolase and the rates of esterification of acyl-CoA into phospholipids and neutral lipids in microsomes were not changed by the dietary alteration. These results support the conclusion that changes of the activity of microsomal chain elongation of palmityl-CoA in various nutritional status result from a rapid synthesis of new enzyme(s).
结合大鼠的营养状况，研究了大鼠肝微粒体中棕榈酰辅酶A向硬脂酰辅酶A的链延长速率。饥饿48小时后降低的微粒体链延长活性，在重新喂食后迅速升高到高水平。正常和重新喂食大鼠中丙二酰辅酶A的表观Km值相同，为1.2×10⁻⁴M。放线菌酮和放线菌素D均阻止了与重新喂食相关的微粒体链延长活性的诱导。此外，饮食改变并未改变微粒体中酰基辅酶A水解酶的活性以及酰基辅酶A酯化形成磷脂和中性脂质的速率。这些结果支持以下结论：在各种营养状况下，棕榈酰辅酶A微粒体链延长活性的变化是由新酶的快速合成引起的。
