کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1927341 1536515 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
GPS, the slope of laurdan generalized polarization spectra, in the study of phospholipid lateral organization and Escherichia coli lipid phases
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
GPS, the slope of laurdan generalized polarization spectra, in the study of phospholipid lateral organization and Escherichia coli lipid phases
چکیده انگلیسی

The dependence of Laurdan generalized polarization (GP) on the excitation or emission wavelengths has been employed, at a descriptive level, to estimate lipid membrane physical state, including the coexistence of phases. In this paper, we introduce GPS, a quantitative, simplified estimation of the GP spectrum slope, and present a novel approach to assessing phase states through a graphical representation of its temperature dependence. The thermotropic profile of GPS allows the detection of the main phase transition of liposomes from model phosphoglycerides and renders a clear identification of Tc, a temperature that is unique for each phospholipid studied, marking the apparent limit between coexistence of phases and liquid crystalline state. Since at this temperature GPS is equal to zero, the tenet that the absence of wavelength effect on generalized polarization always means pure gel phase, can be called into question. Interestingly, GPS allows the discrimination between the thermotropic behavior of vesicles of lipid extracts from Escherichia coli grown at 30, 37, 42 or 45 °C, consistent with the remodeling in phospholipid acyl chain composition induced by changes in culture temperature. Yet in all cases, GPS reports liquid crystalline state at a temperature equal to the growth temperature of the bacteria from which each extract was obtained.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 455, Issue 2, 15 November 2006, Pages 163–174
نویسندگان
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