Ohlrogge J, Savage L, Jaworski J, Voelker T, Post-Beittenmiller D
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312.
Arch Biochem Biophys. 1995 Feb 20;317(1):185-90. doi: 10.1006/abbi.1995.1152.
Expression of a plant lauroyl-acyl carrier protein (ACP) thioesterase in an Escherichia coli strain deficient in beta oxidation results in the accumulation of free fatty acids in the culture. Overall fatty acid production by the cultures is increased severalfold, particularly in the late log and stationary stages of growth. In control E. coli cells, malonyl-ACP levels and rates of fatty acid synthesis are highest during rapid logarithmic growth and decline to undetectable levels in stationary stage. In contrast, in cells expressing plant acyl-ACP thioesterase, malonyl-ACP levels remain high in late log and stationary stage in association with the continued fatty acid production. In addition, the biotin carboxyl carrier protein component of acetyl-CoA carboxylase is expressed at higher levels in cultures expressing the acyl-ACP thioesterase. The data presented indicate that removal of the acyl-ACP products of fatty acid synthesis results in increased production of both malonyl-ACP and fatty acids, which may in turn result from higher activity and/or expression of acetyl-CoA carboxylase.
在缺乏β氧化的大肠杆菌菌株中表达植物月桂酰 - 酰基载体蛋白（ACP）硫酯酶会导致培养物中游离脂肪酸的积累。培养物中总的脂肪酸产量增加了几倍，特别是在对数生长后期和稳定期。在对照大肠杆菌细胞中，丙二酰 - ACP水平和脂肪酸合成速率在快速对数生长期间最高，并在稳定期降至不可检测的水平。相比之下，在表达植物酰基 - ACP硫酯酶的细胞中，丙二酰 - ACP水平在对数生长后期和稳定期仍然很高，这与脂肪酸的持续产生有关。此外，乙酰辅酶A羧化酶的生物素羧基载体蛋白成分在表达酰基 - ACP硫酯酶的培养物中表达水平更高。所呈现的数据表明，脂肪酸合成的酰基 - ACP产物的去除导致丙二酰 - ACP和脂肪酸产量增加，这反过来可能是由于乙酰辅酶A羧化酶的更高活性和/或表达所致。
