Satyanarayana T, Klein H P
J Bacteriol. 1973 Aug;115(2):600-6. doi: 10.1128/jb.115.2.600-606.1973.
Long-chain acyl-coenzyme A (CoA) compounds (palmityl, stearyl, and oleyl) were found to be potent inhibitors of acetyl-CoA synthetase (ACS) of Saccharomyces cerevisiae strain LK2G12 from aerobic, but not from nonaerobic, cells. The effectiveness of the inhibitors of the aerobic enzyme was in the following order: palmityl-CoA < stearyl-CoA < oleyl-CoA. Short-chain acyl-CoA compounds (propionyl, butyryl, and valeryl) and long-chain fatty acids had no effect on ACS from either source. The inhibition by oleyl-CoA was found to be dependent on enzyme concentration, whereas the inhibition by palmityl- and stearyl-CoA was independent of ACS concentration. Inhibition by palmityl-CoA was noncompetitive with respect to both acetate and CoA, and with increasing concentration of inhibitor the pattern was sigmoidal, with a Hill value of 3.24. At maximally inhibitory concentrations of palmityl-CoA, a small amount of enzyme activity remained. This noninhibitable enzyme in aerobic cells was shown not to be of nonaerobic origin.
长链酰基辅酶A（CoA）化合物（棕榈酰、硬脂酰和油酰）被发现是酿酒酵母菌株LK2G12需氧细胞而非厌氧细胞中乙酰辅酶A合成酶（ACS）的有效抑制剂。需氧酶抑制剂的有效性顺序如下：棕榈酰辅酶A＜硬脂酰辅酶A＜油酰辅酶A。短链酰基辅酶A化合物（丙酰、丁酰和戊酰）和长链脂肪酸对两种来源的ACS均无影响。发现油酰辅酶A的抑制作用取决于酶浓度，而棕榈酰和硬脂酰辅酶A的抑制作用与ACS浓度无关。棕榈酰辅酶A的抑制作用在乙酸盐和辅酶A方面均为非竞争性，并且随着抑制剂浓度的增加，抑制模式呈S形，希尔值为3.24。在棕榈酰辅酶A的最大抑制浓度下，仍保留少量酶活性。需氧细胞中这种不可抑制的酶并非源自厌氧细胞。
