کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1956660 1057865 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Backbone Dynamics of Alamethicin Bound to Lipid Membranes: Spin-Echo Electron Paramagnetic Resonance of TOAC-Spin Labels
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Backbone Dynamics of Alamethicin Bound to Lipid Membranes: Spin-Echo Electron Paramagnetic Resonance of TOAC-Spin Labels
چکیده انگلیسی

Alamethicin F50/5 is a hydrophobic peptide that is devoid of charged residues and that induces voltage-dependent ion channels in lipid membranes. The peptide backbone is likely to be involved in the ion conduction pathway. Electron spin-echo spectroscopy of alamethicin F50/5 analogs in which a selected Aib residue (at position n = 1, 8, or 16) is replaced by the TOAC amino-acid spin label was used to study torsional dynamics of the peptide backbone in association with phosphatidylcholine bilayer membranes. Rapid librational motions of limited angular amplitude were observed at each of the three TOAC sites by recording echo-detected spectra as a function of echo delay time, 2τ. Simulation of the time-resolved spectra, combined with conventional EPR measurements of the librational amplitude, shows that torsional fluctuations of the peptide backbone take place on the subnanosecond to nanosecond timescale, with little temperature dependence. Associated fluctuations in polar fields from the peptide could facilitate ion permeation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 94, Issue 7, April 2008, Pages 2698–2705
نویسندگان
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