Sklar L A, Hudson B S, Simoni R D
Proc Natl Acad Sci U S A. 1975 May;72(5):1649-53. doi: 10.1073/pnas.72.5.1649.
The use of fluorescent conjugated polyenoic fatty acids as probes of membrane structure is introduced. alpha- and beta-parinaric acid (cis, trans, trans, cis-, and all trans-9,11,13,15-octadecatetraenoic acid) and synthetic lecithins containing an alpha-parinaric acid chain in position 2 are prepared and their absorption and fluorescence properties are determined. Phase transitions are detected as fluorescence changes at characteristic temperatures when either the free fatty acid probes or the labeled phospholipid probe are included in sonicated aqueous dispersions of L-alpha-dimyristoyl lecithin, L-alpha dipalmitoyl lecithin, or L-alpha-distearoyl lecithin. The phase transitions are detected at about 23 degrees C (dimyristoyl), 44 degrees C (dipalmitoyl), and 53 degrees C (distearoyl lecithin). Binding of alpha-parinaric acid to bovine serum albumin is measured by shifts in the absorption spectrum and enhanced quantum yield of the fatty acid upon binding and by energy transfer between 2 tryptophyl residues in bovine serum albumin and alpha-parinaric acid. Approximately six binding sites are detected. Other applications of these probe molecules, including phase transitions of phospholipid/cholesterol dispersions, induced circular dichroism of parinaric acid bound to albumin, and biosynthetic incorporation of parinaric acid into biological membranes, are discussed.
介绍了使用荧光共轭多烯脂肪酸作为膜结构探针的方法。制备了α-和β-紫黄质酸（顺式、反式、反式、顺式 - 和全反式 - 9,11,13,15 - 十八碳四烯酸）以及在2位含有α-紫黄质酸链的合成卵磷脂，并测定了它们的吸收和荧光性质。当游离脂肪酸探针或标记的磷脂探针包含在L-α-二肉豆蔻酰卵磷脂、L-α-二棕榈酰卵磷脂或L-α-二硬脂酰卵磷脂的超声水相分散体中时，在特征温度下作为荧光变化检测相变。在约23℃（二肉豆蔻酰）、44℃（二棕榈酰）和53℃（二硬脂酰卵磷脂）检测到相变。通过吸收光谱的变化、结合时脂肪酸量子产率的提高以及牛血清白蛋白中两个色氨酸残基与α-紫黄质酸之间的能量转移来测量α-紫黄质酸与牛血清白蛋白的结合。检测到大约六个结合位点。讨论了这些探针分子的其他应用，包括磷脂/胆固醇分散体的相变、与白蛋白结合的紫黄质酸的诱导圆二色性以及紫黄质酸在生物膜中的生物合成掺入。
