Partitioning of gramicidin A' between coexisting fluid and gel phospholipid phases.
Partitioning of gramicidin A' between coexisting fluid and gel phospholipid phases.
复制标题
短杆菌肽 A 在共存的液体相和凝胶磷脂相之间的分配。
DOI：
10.1016/0005-2736(93)90400-t
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Feigenson,GW
中科院分区：
文献类型：
--
作者：
Dibble,AR;Yeager,MD;Feigenson,GW
研究了短杆菌肽 A' 在流体相和凝胶相共存的四种二元磷脂混合物中的分配行为。通过分析自旋标记的磷脂酰胆碱对短杆菌肽 A' 色氨酸荧光的猝灭，确定液相中的平衡肽浓度与凝胶相中的平衡肽浓度之比（即分配系数 Kp）。分配系数用于衡量短杆菌肽 A' 在所分析的四种类型的凝胶相中的相对溶解度。凝胶相的组成完全是 Ca(二油酰磷脂酰丝氨酸)2(Ca(di18:1-PS)2)，或富含二硬脂酰磷脂酰胆碱 (di18:0-PC)、二棕榈酰磷脂酰胆碱 (di16:0-PC) 或二肉豆蔻酰磷脂酰胆碱 (di14:0-PC)。当凝胶相富含Ca(di18:1-PS)2或di18:0-PC时，凝胶相中缺乏短杆菌肽A':Kp~30；当凝胶相富含di16:0-PC时，Kp~10；当凝胶相富含di14:0-PC时，Kp~1。短杆菌肽 A' 的长度与本体凝胶相中磷脂酰基链的长度之间的疏水性不匹配在 di18:1-PS 和 di18:0-PC 中最大，在 di16:0-PC 中居中，在 di14:0-PC 中最小。这里给出的 Kp 测量结果与短杆菌肽 A' 在凝胶相中溶解度的增加以及疏水性失配的减少一致。
The partitioning behavior of gramicidin A′ was investigated in four binary phospholipid mixtures with coexisting fluid and gel phases. The ratio of the equilibrium peptide concentration in the fluid phase to that in the gel phase (i.e., the partition coefficient,Kp) was determined by analysis of the quenching of gramicidin A′ tryptophanyl fluorescence by a spin-labeled phosphatidylcholine. The partition coefficient was used as a measure of the relative solubility of gramicidin A′ in the four types of gel phases analyzed. The composition of the gel phase was entirely Ca(dioleoylphosphatidylserine)2(Ca(di18:1-PS)2), or was rich in either distearoylphosphatidylcholine (di18:0-PC), dipalmitoylphosphatidylcholine (di16:0-PC), or dimyristoylphosphatidylcholine (di14 : 0-PC) Except in the last case, the gel phase was depleted of gramicidin A′:Kp∼ 30 when the gel phase was Ca(di18:1-PS)2or di18:0-PC-rich,Kp∼ 10 when the gel phase was di16:0-PC-rich, andKp∼ 1 when the gel phase was di14:0-PC-rich. The hydrophobic mismatch between the length of gramicidin A′ and the length of the phospholipid acyl chains in the bulk gel phase is greatest with di18:1-PS and di18:0-PC, intermediate with di16:0-PC, and least with di14:0-PC. TheKpmeasurements presented here are consistent with increasing solubility of gramicidin A′ in the gel phase with decreasing hydrophobic mismatch.