Using infrared spectroscopy of cyanylated cysteine to map the membrane binding structure and orientation of the hybrid antimicrobial peptide CM15.
Using infrared spectroscopy of cyanylated cysteine to map the membrane binding structure and orientation of the hybrid antimicrobial peptide CM15.
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DOI：
10.1021/bi200903p
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发表时间：
2011-12-27
期刊：
影响因子：
2.9
通讯作者：
Londergan, Casey H.
中科院分区：
文献类型：
--
作者：
Alfieri, Katherine N.;Vienneau, Alice R.;Londergan, Casey H.
合成的抗菌肽CM 15是来自天蚕素和蜂毒肽的N-末端序列的杂合物，已被证明是非常有效的。根据先前的定点自旋标记研究，推测其作用机制涉及孔形成。本研究通过红外光谱中独特CN伸缩带的频率和线形，研究了CM 15的四种单位点β-硫氰基丙氨酸变体，其中人工氨基酸侧链作为其局部环境的振动报告子。圆二色性实验表明，人工侧链的位置上的膜结合的二级结构的CM 15肽只有很小的扰动影响。将所有变体肽置于缓冲溶液中，与十二烷基磷脂酰胆碱胶束接触，并与由E.大肠杆菌极性脂质提取物。在每个站点，CN拉伸带报告不同的行为。时间依赖性衰减全反射红外光谱，也收集了每一个变种，因为它是允许重塑E。大肠杆菌脂质囊泡。这些实验同意先前提出的环形孔的形成，其中每个肽发现自己在一个越来越均匀和弯曲的局部环境中，没有明显的肽-肽相互作用。这项工作也表明了极好的灵敏度的SCN伸缩振动的肽-脂质界面结构的微小变化。
The synthetic antimicrobial peptide CM15, a hybrid of N-terminal sequences from cecropin and melittin peptides, has been shown to be extremely potent. Its mechanism of action has been speculated to involve pore formation based on prior site-directed spin labeling studies. This study examines four single-site β-thiocyanatoalanine variants of CM15 in which the artificial amino acid side chain acts as a vibrational reporter of its local environment through the frequency and lineshape of the unique CN stretching band in the infrared spectrum. Circular dichroism experiments indicate that the placements of the artificial side chain have only small perturbative effects on the membrane-bound secondary structure of the CM15 peptide. All variant peptides were placed in buffer solution, in contact with dodecylphosphatidylcholine micelles, and in contact with vesicles formed from E. coli polar lipid extract. At each site, the CN stretching band reports a different behavior. Time-dependent attenuated total reflectance infrared spectra were also collected for each variant as it was allowed to remodel the E. coli lipid vesicles. These experiments agree with the previously proposed formation of toroidal pores, in which each peptide finds itself in an increasingly homogeneous and curved local environment without apparent peptide-peptide interactions. This work also demonstrates the excellent sensitivity of the SCN stretching vibration to small changes in peptide-lipid interfacial structure.
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影响因子：
3.3
作者：
Edelstein, Lena;Stetz, Matthew A.;McMahon, Heather A.;Londergan, Casey H.
通讯作者：
Londergan, Casey H.
影响因子：
2.9
作者：
ANDREU, D;MERRIFIELD, RB;BOMAN, HG
通讯作者：
BOMAN, HG
影响因子：
3.5
作者：
ANDREU, D;UBACH, J;BOMAN, HG
通讯作者：
BOMAN, HG
DOI：
10.1073/pnas.86.23.9159
发表时间：
1989-12-01
影响因子：
11.1
作者：
LEE, JY;BOMAN, A;BOMAN, HG
通讯作者：
BOMAN, HG
影响因子：
15
作者：
Fafarman, Aaron T.;Sigala, Paul A.;Herschlag, Daniel;Boxer, Steven G.
通讯作者：
Boxer, Steven G.