Cassel D L, Ragona D G, Carriero L, Kempe J A, Conner R L
Biochim Biophys Acta. 1981 Jan 26;663(1):121-33. doi: 10.1016/0005-2760(81)90199-5.
Tetrahymena pyriformis W cells were grown with short- and long-chain, odd and even normal fatty acid supplements. Tris acetate addition had no effect on the fatty acyl composition of the glycerophospholipids or sphingolipids, while Tris propionate supplementation led to a marked increase in odd normal fatty acids at the expense of even normal acids in both classes of complex lipids. This enhancement of odd normal acids permitted the identification of 17:1 delta 9(n), 17:2 delta 6,9(n), 17:2 delta 9,12(n), 17:3 delta 6,9,12(n), 19:1 delta 9(n), 19:2 delta 9,12(n) and 19:3 delta 6,9,12(n) by oxidation with periodate-permanganate and examination of the short-chain fragments. Supplementation with pentadecanoic acid (15:0(n)) led to an increase in the proportions of normal C15, C17 and C19 acids. The increase in C15 acids primarily reflected a rise in 15:0(n), whereas the rise in the levels of C17 and C19 acids was accounted for by an elevation of unsaturated acids. Growth with heptadecanoic acid (17:0(n)) resulted in substantial increases in unsaturated normal C17 and C19 fatty acids, while nonadecanoic acid (19:0(n)) addition led only to an increase in the proportion of unsaturated C19 acids. Retroconversion of these saturated, odd normal long chain fatty acid supplements was limited. Supplementation with arachidic acid (20:0(n)) resulted in only a marginal increase (1.4%) in normal C20 fatty acids of both the glycerophospholipids and the mild alkali labile neutral lipids and provided no evidence that desaturation occurred. The release of 14CO2 from [1-14C]arachidic acid when incubated with the ciliates indicated that this long-chain saturate is accumulated, activated and degraded. Normal C16-C19 saturated fatty acids are substrates for the delta 9 desaturase. The delta 11 isomers arise by chain elongation. Normal C16-C19 delta 9 monoenoic acids are substrates for the delta 12 desaturase. Normal C16-C18 delta 9 monoenes, normal C16-C19 delta 9,12 dienes and 18:1 delta 11(n) are desaturated at the C-6,7 position.
梨形四膜虫W细胞在添加短链和长链、奇数和偶数正常脂肪酸的条件下生长。添加醋酸三乙胺对甘油磷脂或鞘脂的脂肪酰基组成没有影响，而添加丙酸三乙胺导致两类复合脂质中奇数正常脂肪酸显著增加，偶数正常脂肪酸减少。奇数正常脂肪酸的这种增加使得通过高碘酸盐-高锰酸盐氧化并检查短链片段能够鉴定出17:1Δ9(n)、17:2Δ6,9(n)、17:2Δ9,12(n)、17:3Δ6,9,12(n)、19:1Δ9(n)、19:2Δ9,12(n)和19:3Δ6,9,12(n)。添加十五烷酸(15:0(n))导致正常C15、C17和C19酸的比例增加。C15酸的增加主要反映了15:0(n)的升高，而C17和C19酸水平的升高是由不饱和酸的增加引起的。用十七烷酸(17:0(n))培养导致不饱和正常C17和C19脂肪酸大量增加，而添加十九烷酸(19:0(n))仅导致不饱和C19酸比例增加。这些饱和的奇数正常长链脂肪酸补充剂的逆向转化有限。添加花生酸(20:0(n))仅导致甘油磷脂和轻度碱不稳定中性脂质的正常C20脂肪酸略有增加(1.4%)，且没有证据表明发生了去饱和作用。当与纤毛虫一起孵育时，[1-14C]花生酸释放出14CO2，表明这种长链饱和脂肪酸被积累、活化和降解。正常的C16-C19饱和脂肪酸是Δ9去饱和酶的底物。Δ11异构体通过链延长产生。正常的C16-C19Δ9单烯酸是Δ12去饱和酶的底物。正常的C16-C18Δ9单烯酸、正常的C16-C19Δ9,12二烯酸和18:1Δ11(n)在C-6,7位去饱和。
