Ilton M, Jevans A W, McCarthy E D, Vance D, White H B, Bloch K
Proc Natl Acad Sci U S A. 1971 Jan;68(1):87-91. doi: 10.1073/pnas.68.1.87.
The multienzyme complex from Mycobacterium phlei which catalyzes the synthesis of long chain fatty acids from acetyl-CoA and malonyl-CoA requires a heat-stable fraction (stimulating factor, SF) for activity. Fractionation of heat-treated M. phlei extracts affords two stimulatory subfractions, one of which (SF(2)) can be replaced by FMN. The other (SF(1)) is further separable into 3 polysaccharides (PS(I), PS(II), and PS(III)). PS(I) contains about 95% 3-O-methylmannose and 5% mannose; the sugar composition of PS(II) and PS(III) is about 55% 6-O-methylglucose and 45% glucose for both. Each of the three purified polysaccharides, in combination with FMN, substitutes for the crude stimulating factor. The polysaccharides exert their effect on the fatty acid synthetase by lowering the K(m) for acetyl-CoA about 50-fold.
来自草分枝杆菌的多酶复合物可催化由乙酰辅酶A和丙二酰辅酶A合成长链脂肪酸，其活性需要一种热稳定组分（刺激因子，SF）。对热处理的草分枝杆菌提取物进行分级分离可得到两种刺激亚组分，其中一种（SF(2)）可被FMN替代。另一种（SF(1)）可进一步分离成3种多糖（PS(I)、PS(II)和PS(III)）。PS(I)含有约95%的3-O-甲基甘露糖和5%的甘露糖；PS(II)和PS(III)的糖组成均约为55%的6-O-甲基葡萄糖和45%的葡萄糖。三种纯化的多糖中的每一种与FMN结合后，都可替代粗刺激因子。这些多糖通过将乙酰辅酶A的K(m)降低约50倍，对脂肪酸合成酶发挥作用。
