Firestone L L, Janoff A S, Miller K W
Biochim Biophys Acta. 1987 Mar 26;898(1):90-6. doi: 10.1016/0005-2736(87)90112-x.
The cis- and trans-alkenols are equally potent general anesthetics but, respectively, lower and raise the gel-to-liquid crystalline phase transition temperature of saturated phosphatidylcholines (Pringle, M.J. and Miller, K.W. (1978) Biochem. Biophys. Res. Commun. 85, 1191-1198). Here we show that although this differential effect is somewhat reduced when a double bond is introduced into the sn-2 position of phosphatidylcholine, it is abolished when the ethanolamine head group is substituted for the choline head group in dimyristoyl lipids at neutral pH. At high pH, however, dimyristoylphosphatidylethanolamine assumes a negative charge, and its phase transition temperature drops to a value close to that for the corresponding phosphatidylcholine. Under these conditions the differential effect of the alkenol isomers is restored; the cis-alkenol lowers, while the trans-alkenol raises, the phase transition temperature of deprotonated dimyristoylphosphatidylethanolamine. Thus, the differential effects of cis- and trans-alkenols on the gel-to-liquid crystalline phase transition are dependent on the physical chemical characteristics of the polar region of the perturbed lipid species, but only weakly on that of the acyl region.
顺式和反式链烯醇是同等有效的全身麻醉剂，但分别降低和提高饱和磷脂酰胆碱的凝胶-液晶相转变温度（普林格尔，M.J.和米勒，K.W.（1978年）《生物化学与生物物理研究通讯》85卷，1191 - 1198页）。我们在此表明，虽然当在磷脂酰胆碱的sn - 2位引入双键时这种差异效应有所降低，但当中性pH下二肉豆蔻酰脂质中的胆碱头部基团被乙醇胺头部基团取代时，这种差异效应就消失了。然而，在高pH下，二肉豆蔻酰磷脂酰乙醇胺带负电荷，其相转变温度降至接近相应磷脂酰胆碱的相转变温度的值。在这些条件下，链烯醇异构体的差异效应得以恢复；顺式链烯醇降低去质子化的二肉豆蔻酰磷脂酰乙醇胺的相转变温度，而反式链烯醇则提高其相转变温度。因此，顺式和反式链烯醇对凝胶-液晶相转变的差异效应取决于受扰动脂质种类极性区域的物理化学特性，但对酰基区域的特性依赖性较弱。
