Reed J R, Vanderwel D, Choi S, Pomonis J G, Reitz R C, Blomquist G J
Department of Biochemistry, University of Nevada, Reno 89557-0014.
Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):10000-4. doi: 10.1073/pnas.91.21.10000.
An unusual mechanism for hydrocarbon biosynthesis is proposed from work examining the formation of (Z)-9-tricosene (Z9-23:Hy), the major sex pheromone component of the female housefly, Musca domestica. Incubation of (Z)-15-[1-14C]- and (Z)-15-[15,16-3H2]tetracosenoic acid (24:1 fatty acid) with microsomes from houseflies gave equal amounts of [3H]Z9-23:Hy and 14CO2. The formation of CO2 and not CO, as reported for hydrocarbon formation in plants, animals, and microorganisms [Dennis, M. & Kolattukudy, P. E. (1992) Proc. Natl. Acad. Sci. USA 89, 5306-5310], was verified by trapping agents and by radio-GLC analysis. Incubation of (Z)-15-[15,16-3H2]tetracosenoyl-CoA with microsomal preparations in the presence of NADPH and O2 gave almost equal amounts of (Z)-15-3H2]tetrasosenal (24:1 aldehyde) and Z9-23:Hy. Addition of increasing amounts of hydroxylamine (aldehyde trapping agent) caused a decrease in hydrocarbon formation with a concomitant increase in oxime (aldehyde derivative) formation. The 24:1 aldehyde was efficiently converted to (Z)-9-tricosene only in the presence of both NADPH and O2. Bubbling carbon monoxide (20:80 CO/O2) or including an antibody against housefly cytochrome P450 reductase inhibited the formation Z9-23:Hy from 24:1 aldehyde. These data demonstrate an unusual mechanism for hydrocarbon formation in insects in which the acyl-CoA is reduced to the corresponding aldehyde and then carbon-1 is removed as CO2. The requirement for NADPH and O2 and the inhibition by CO and the antibody to cytochrome P450 reductase strongly implicate the participation of a cytochrome P450 in this reaction.
通过对家蝇雌性主要性信息素成分（Z）-9-二十三碳烯（Z9-23:Hy）形成过程的研究，提出了一种不同寻常的烃生物合成机制。将（Z）-15-[1-14C]-和（Z）-15-[15,16-3H2]二十四碳烯酸（24:1脂肪酸）与家蝇微粒体一起温育，产生了等量的[3H]Z9-23:Hy和14CO2。与植物、动物和微生物中烃形成过程的报道[丹尼斯，M.和科拉图库迪，P.E.（1992年）美国国家科学院院刊89，5306-5310]不同，这里形成的是CO2而非CO，这一点通过捕集剂和放射性气相色谱分析得到了验证。在NADPH和O2存在的情况下，将（Z）-15-[15,16-3H2]二十四碳烯酰辅酶A与微粒体制剂一起温育，产生了几乎等量的（Z）-15-3H2]二十四碳烯醛（24:1醛）和Z9-23:Hy。加入越来越多的羟胺（醛捕集剂）会导致烃形成减少，同时肟（醛衍生物）形成增加。只有在NADPH和O2都存在的情况下，24:1醛才能有效地转化为（Z）-9-二十三碳烯。通入一氧化碳（20:80 CO/O2）或加入抗家蝇细胞色素P450还原酶的抗体，会抑制由24:1醛形成Z9-23:Hy。这些数据证明了昆虫中烃形成的一种不同寻常的机制，即酰基辅酶A被还原为相应的醛，然后碳-1以CO2的形式被去除。对NADPH和O2的需求以及CO和细胞色素P450还原酶抗体的抑制作用强烈表明细胞色素P450参与了这一反应。
