Paris S, Samuel D, Jacques Y, Gache C, Franchi A, Ailhaud G
Eur J Biochem. 1978 Feb 1;83(1):235-43. doi: 10.1111/j.1432-1033.1978.tb12088.x.
Fatty acids enter the cultured cardiac cells from chicken embryo through two mechanisms, one involving a saturable process, the other resembling passive diffusion. Studies of the saturable component, at fixed concentrations of palmitate or of oleate and at increasing concentrations of albumin, show that this protein increases the rate of palmitate uptake with a maximum at palmitate/albumin molar ratios between 7 and 10 while it decreases the rate of oleate uptake under all conditions. Albumin cannot be replaced by other serum proteins; its effect is specific to saturated fatty acids, can be mimicked by the detergent Tween 40 and involves the binding of the fatty acid to the protein, prior to its delivery to the cell. Both with labelled saturated and unsaturated fatty acids the presence of albumin lowers the proportion of unesterified fatty acids and enhances the proportion of esterified fatty acids recovered in the cardiac cell after uptake. A similar effect of albumin was also found with hepatocytes and permanent cell lines. A specific role for serum albumin is presented, which assumes a 'dispersing' effect of this protein towards dimers (or higher aggregates) of saturated fatty acids and the entry of fatty acids into the cell as monomers.
脂肪酸通过两种机制进入鸡胚培养的心肌细胞，一种涉及可饱和过程，另一种类似于被动扩散。在棕榈酸或油酸浓度固定且白蛋白浓度不断增加的情况下，对可饱和成分的研究表明，这种蛋白质会增加棕榈酸的摄取速率，在棕榈酸/白蛋白摩尔比为7至10时达到最大值，而在所有条件下都会降低油酸的摄取速率。白蛋白不能被其他血清蛋白替代；其作用对饱和脂肪酸具有特异性，可被去污剂吐温40模拟，且在脂肪酸传递至细胞之前涉及脂肪酸与蛋白质的结合。无论是标记的饱和脂肪酸还是不饱和脂肪酸，白蛋白的存在都会降低未酯化脂肪酸的比例，并提高摄取后在心肌细胞中回收的酯化脂肪酸的比例。在肝细胞和永久细胞系中也发现了白蛋白的类似作用。血清白蛋白具有特定作用，即假定该蛋白质对饱和脂肪酸二聚体（或更高聚集体）具有“分散”作用，并使脂肪酸以单体形式进入细胞。
