Borrebaek B
Acta Physiol Scand. 1975 Dec;95(4):448-56. doi: 10.1111/j.1748-1716.1975.tb10073.x.
Rates of acylation of carnitine and glycerophosphate in suspensions of isolated rat liver mitochondria were measured at varying levels of palmitate and coenzyme A in the presence of ATP. Addition of glycerophosphate caused considerable reduction in carnitine acylation at low, but not at high palmitate levels. Glycerophosphate acylation was less reduced by added carnitine. These results can be explained by a lower Km(acyl-CoA) in glycerophosphate acylation than in carnitine acylation. High levels of free coenzyme A caused inhibition of carnitine acylation, while the inhibitory effect of glycerophosphate acylation was small. Competition between palmitate and acyl-CoA for binding sites on protein (e.g., albumine added to the mitochondrial suspensions) was indicated by stimulation of carnitine acylation by palmitate with palmityl-CoA added as substrate in the absence of ATP. Refeeding a carbohydrate-rich diet to previously fasted rats resulted in increased glycerophosphate acylation and decreased carnitine acylation in isolated liver mitochondria.
在ATP存在的情况下，于不同水平的棕榈酸和辅酶A条件下，测定了分离的大鼠肝脏线粒体悬浮液中肉碱和甘油磷酸的酰化速率。添加甘油磷酸在低棕榈酸水平时会导致肉碱酰化显著降低，但在高棕榈酸水平时则不会。添加肉碱对甘油磷酸酰化的降低作用较小。这些结果可以通过甘油磷酸酰化中较低的Km（酰基辅酶A）来解释，其低于肉碱酰化中的Km（酰基辅酶A）。高水平的游离辅酶A会抑制肉碱酰化，而甘油磷酸酰化的抑制作用较小。在不存在ATP的情况下，以棕榈酰辅酶A作为底物添加棕榈酸时，棕榈酸对肉碱酰化有刺激作用，这表明棕榈酸和酰基辅酶A在蛋白质（如添加到线粒体悬浮液中的白蛋白）上的结合位点存在竞争。给先前禁食的大鼠重新喂食富含碳水化合物的饮食，会导致分离的肝脏线粒体中甘油磷酸酰化增加，肉碱酰化减少。
