Nothelfer H G, Barckhaus R H, Spener F
Biochim Biophys Acta. 1977 Dec 21;489(3):370-80. doi: 10.1016/0005-2760(77)90157-6.
In course of a study of fatty acid synthetase in higher plants, non-green cell suspension cultures of Glycine max (soybean) served as model tissues. For the first time, a fatty acid synthesizing system was characterized in cell cultures of higher plants and was found to be solely located in proplastids of the cells. Optimum activity of the fatty acid synthesizing system in proplastids was observed between pH 8.0 and 8.2; with [1-14C]acetate as substrate, cofactors required were CoA, ATP, Mn2+, Mg2+, HCO3-, NADH and NADPH. The system was more sensitive towards NADH than NADHP. [1-14C]Acetate,[2-14C]-malonate and [3-14C]pyruvate served as precursors for fatty acids, indicating the presence of pyruvate dehydrogenase activity in proplastids. In disrupted proplastids, [2-14C]malonylCoA was a better precursor than [1-14C]acetylCoA. After incubation of proplastids with [2-14C]malonate, a small shift, from palmitic acid to higher homologs, of label incorporated was observed, as compared to incorporation of label from [1-14C]acetate and [3-14C]pyruvate. Under the conditions of the experiment, only small amounts of polyunsaturated fatty acids, the main fatty acid components of this organelle, were synthesized. In respect to fatty acid synthesis, the non-green cell suspension culture resembles photosynthetic leaf tissue.
在对高等植物脂肪酸合成酶的研究过程中，大豆非绿色细胞悬浮培养物被用作模型组织。首次在高等植物细胞培养物中对脂肪酸合成系统进行了表征，发现该系统仅位于细胞的前质体中。在前质体中，脂肪酸合成系统的最佳活性在pH 8.0至8.2之间观察到；以[1-14C]乙酸盐为底物时，所需的辅因子有辅酶A、ATP、Mn2+、Mg2+、HCO3-、NADH和NADPH。该系统对NADH比对NADHP更敏感。[1-14C]乙酸盐、[2-14C]丙二酸盐和[3-14C]丙酮酸用作脂肪酸的前体，表明前质体中存在丙酮酸脱氢酶活性。在破碎的前质体中，[2-14C]丙二酰辅酶A比[1-14C]乙酰辅酶A是更好的前体。与[1-14C]乙酸盐和[3-14C]丙酮酸掺入的标记相比，用[2-14C]丙二酸盐孵育前质体后，观察到掺入标记从棕榈酸向更高同系物有小的偏移。在实验条件下，仅合成了少量的多不饱和脂肪酸，而多不饱和脂肪酸是该细胞器的主要脂肪酸成分。就脂肪酸合成而言，非绿色细胞悬浮培养物类似于光合叶片组织。
