Fluorescence and UV resonance Raman study of peptide-vesicle interactions of human cathelicidin LL-37 and its F6W and F17W mutants.
Fluorescence and UV resonance Raman study of peptide-vesicle interactions of human cathelicidin LL-37 and its F6W and F17W mutants.
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DOI：
10.1021/bi900996q
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发表时间：
2009-12-01
期刊：
影响因子：
2.9
通讯作者：
Kim, Judy E.
中科院分区：
文献类型：
--
作者：
Gable, Jonathan E.;Schlamadinger, Diana E.;Cogen, Anna L.;Gallo, Richard L.;Kim, Judy E.
LL-37是凯萨林菌素家族中的广谱人抗微生物肽。以最小抑制浓度和囊泡渗漏形式的效力测定表明，单色氨酸突变体F6 W和F17 W在杀死细菌和破坏膜方面与天然的无色氨酸的LL-37肽一样有效。稳态荧光和紫外共振拉曼光谱的F6 W和F17 W揭示这些色氨酸残基的分子细节。与纯蒸馏水中相比，碳酸根离子存在下F6 W和F17 W的局部环境极性、吲哚N-H部分的氢键强度和旋转自由度均降低;这些结果与碳酸根离子存在下诱导的低聚核中α-螺旋LL-37的疏水区域的掩埋一致。碳酸盐诱导的F6 W和F17 W的α-螺旋形式的光谱性质的差异反映了F6 W附近局部赖氨酸残基的存在，这使得F6 W的微环境比F17 W的微环境更极性。在脂质囊泡的存在下，突变体经历额外的环境极性，氢键强度和旋转自由度的损失。利用溴化脂质的猝灭实验表明，两种突变体中的色氨酸残基基本上与双层中心等距，并且更靠近双层中心的溴（在9、10位置）比更靠近头部基团的溴（6、7位置）更有效地猝灭荧光。这些结果支持LL-37破坏膜的地毯或环形孔机制，并表明色氨酸突变体和敏感的光谱工具的组合可能提供重要的抗微生物作用的分子线索。
LL-37 is a broad-spectrum human antimicrobial peptide in the cathelicidin family. Potency assays in the form of minimal inhibitory concentration and vesicle leakage indicate that the single-tryptophan mutants, F6W and F17W, are as effective at killing bacteria and disrupting membranes as the native, tryptophan-free LL-37 peptide. Steady-state fluorescence and UV resonance Raman spectroscopy of F6W and F17W reveal molecular details of these tryptophan residues. The local environment polarity, hydrogen-bond strength of the indole N-H moiety, and rotational freedom decrease for both F6W and F17W in the presence of carbonate ions relative to in pure distilled water; these results are consistent with burial of the hydrophobic region of α-helical LL-37 in oligomeric cores induced in the presence of carbonate ions. Differences in the spectroscopic properties of the carbonate-induced α-helical forms of F6W and F17W reflect the presence of a local lysine residue near F6W that makes the microenvironment of F6W more polar than that of F17W. In the presence of lipid vesicles, the mutants undergo additional loss of environment polarity, hydrogen-bond strength, and rotational freedom. Quenching experiments utilizing brominated lipids reveal that the tryptophan residue in both mutants are essentially equidistant from the bilayer center, and that bromines closer to the bilayer center, in the 9,10 positions, quench fluorescence more efficiently than those closer to the head groups (6,7 positions). These results support carpeting or toroidal pore mechanisms of membrane disruption by LL-37, and demonstrate that the combination of tryptophan mutants and sensitive spectroscopic tools may provide important molecular clues of antimicrobial action.
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DOI：
10.1073/pnas.0803815105
发表时间：
2008-10-28
影响因子：
11.1
作者：
Gryllos, Ioannis;Tran-Winkler, Hien J.;Wessels, Michael R.
通讯作者：
Wessels, Michael R.
影响因子：
2.9
作者：
DEKROON, AIP;SOEKARJO, MW;DEKRUIJFF, B
通讯作者：
DEKRUIJFF, B
影响因子：
2.9
作者：
Matsuzaki, K;Murase, O;Miyajima, K
通讯作者：
Miyajima, K
影响因子：
2
作者：
Clayton, AHA;Sawyer, WH
通讯作者：
Sawyer, WH
影响因子：
4.8
作者：
Dorschner, RA;Lopez-Garcia, B;Gallo, RL
通讯作者：
Gallo, RL