Dempsey C E, Bazzo R, Harvey T S, Syperek I, Boheim G, Campbell I D
Biochemistry Department, Oxford University, UK.
FEBS Lett. 1991 Apr 9;281(1-2):240-4. doi: 10.1016/0014-5793(91)80402-o.
The structure and dynamic properties of bee venom melittin and a synthetic analogue, [Ala14]-melittin (melittin P14A), are compared, using high resolution 1H nuclear magnetic resonance (NMR) spectroscopy and amide exchange measurements in methanol. P14A is shown to adopt a regular, stable alpha-helical conformation in solution without the flexibility around the Pro-14 residue found in melittin. P14A has twice the hemolytic activity of melittin but is less able to induce voltage-dependent ion conductance in planar bilayers. The results indicate that helix flexibility afforded by the Pro-14 residue promotes the ability of melittin to adopt the transbilayer associates thought to underlie ion translocation.
使用高分辨率1H核磁共振（NMR）光谱和甲醇中的酰胺交换测量方法，比较了蜂毒溶血肽及其合成类似物[Ala14]-溶血肽（溶血肽P14A）的结构和动态特性。结果表明，P14A在溶液中呈现规则、稳定的α-螺旋构象，不像溶血肽那样在Pro-14残基周围具有灵活性。P14A的溶血活性是溶血肽的两倍，但在平面双分子层中诱导电压依赖性离子电导的能力较弱。结果表明，Pro-14残基提供的螺旋灵活性促进了溶血肽形成被认为是离子转运基础的跨双分子层缔合体的能力。
