这种 18 个氨基酸的两亲性螺旋肽 Ac-DWFKAFYDKVAEKFKEAF-NH₂ 能促使胆固醇从磷脂中分离出来，即使胆固醇的摩尔分数低至 0.3 也能形成胆固醇结晶体。在没有胆固醇的情况下，该肽对纯磷脂酰胆碱膜的渗透程度大于对磷脂酰胆碱和胆固醇双层膜的渗透程度。该肽在缓冲液中的圆二色谱表明其会自我缔合，从而形成螺旋含量更高的结构。然而，在有脂质存在的情况下，该肽在更宽的浓度范围内保持螺旋结构。该肽在加热时会发生热转变。胆固醇对肽的二级结构影响不大；然而，在没有胆固醇的情况下，色氨酸发射强度增加表明螺旋在从膜中去除胆固醇后会更深入地渗透。这些模型系统的结果表明了肽与脂质相互作用的变化，这可能与该肽所观察到的生物学特性有关。

The 18-amino acid amphipathic helical peptide Ac-DWFKAFYDKVAEKFKEAF-NH(2) promotes the separation of cholesterol from the phospholipid, resulting in the formation of cholesterol crystallites, even at mole fractions of cholesterol as low as 0.3. The peptide exerts a greater degree of penetration into membranes of pure phosphatidylcholine in the absence of cholesterol than into bilayers of phosphatidylcholine and cholesterol. The circular dichroism spectrum of the peptide in buffer indicates that it self-associates, leading to the formation of structures with higher helical content. However, in the presence of lipid, the peptide remains helical over a larger concentration range. The peptide undergoes a thermal transition on heating. Cholesterol has little effect on the secondary structure of the peptide; however, increased Trp emission intensity in the absence of cholesterol indicates a deeper penetration of the helix upon removal of cholesterol from the membrane. The results with these model systems demonstrate changes in peptide-lipid interactions that may be related to the observed biological properties of this peptide.

单字母 Ac-DWFKAFYDKVAEKFKEAF-NH2
多字母 Ac-Asp-Trp-Phe-Lys-Ala-Phe-Tyr-Asp-Lys-Val-Ala-Glu-Lys-Phe-Lys-Glu-Ala-Phe-NH2
氨基酸个数 18
分子式 C114H156O28N24
平均分子量(MW) 2310.6
精确分子量(Exact Mass)(MW) 2309.15
等电点(PI) 10.01
pH=7.0时的净电荷数 1
GRAVY -0.59
亲水残基比例 0.1
消光系数 6990
溶解建议 亲水

参考文献：
Epand RM, Epand RF, Sayer BG, Melacini G, Palgulachari MN, Segrest JP, Anantharamaiah GM. An apolipoprotein AI mimetic peptide: membrane interactions and the role of cholesterol. Biochemistry. 2004 May 4;43(17):5073-83. doi: 10.1021/bi049786u. PMID: 15109266.