Epand R M, Shai Y, Segrest J P, Anantharamaiah G M
Department of Biochemistry, McMaster University, Hamilton, ON, Canada.
Biopolymers. 1995;37(5):319-38. doi: 10.1002/bip.360370504.
The amphipathic helix, in which hydrophobic and hydrophilic residues are grouped on opposing faces, is a structural motif found in many peptides and proteins that bind to membranes. One of the physical properties of membranes that can be altered by the binding of amphipathic helices is membrane monolayer curvature strain. Class A amphipathic helices, which are present in exchangeable plasma lipoproteins, can stabilize membranes by reducing negative monolayer curvature strain; proline-punctuated class A amphipathic helical segments are particularly effective in this regard. This property is suggested to be associated with some of the beneficial biological effects of this protein. On the other hand, lytic amphipathic helical peptides can act by increasing negative curvature strain or by forming pores composed of helical clusters. Thus, different amphipathic helical peptides can be membrane stabilizing or be lytic to membranes, depending on the structural motif of the helix, which in turn determines the nature of its association with membranes. Features of these peptides that are responsible for their specific properties are discussed.
两亲性螺旋中，疏水残基和亲水残基分布在相对的面上，是在许多与膜结合的肽和蛋白质中发现的一种结构基序。两亲性螺旋结合可改变的膜的物理性质之一是膜单层曲率应变。存在于可交换血浆脂蛋白中的A类两亲性螺旋可通过降低负单层曲率应变来稳定膜；脯氨酸间断的A类两亲性螺旋片段在这方面特别有效。该特性被认为与这种蛋白质的一些有益生物学效应有关。另一方面，溶解性两亲性螺旋肽可通过增加负曲率应变或通过形成由螺旋簇组成的孔来发挥作用。因此，不同的两亲性螺旋肽可以稳定膜或对膜具有溶解性，这取决于螺旋的结构基序，而这又决定了其与膜结合的性质。本文讨论了这些肽产生特定性质的特征。
