Determination of membrane lipid phase transition temperature from 13C-NMR intensities

Biology Department, Carleton University and N.R.C., Ottawa, Canada.
Journal of Biochemical and Biophysical Methods (Impact Factor: 1.81). 04/1990; 20(4):353-6. DOI: 10.1016/0165-022X(90)90097-V
Source: PubMed


A new and simple approach for the determination of the temperature of gel-to-liquid crystalline phase transitions (Tc) of biological (chloroplast) membrane lipids from 13C-NMR resonance intensities is proposed. The variation of intensity of a temperature-sensitive NMR resonance is monitored by recording the spectra of the sample at a range of temperatures. From such a series of spectra recorded at different temperatures, a temperature-insensitive resonance is located. Then the ratio of the intensity of the temperature-sensitive to the intensity of the temperature-insensitive resonance is calculated from each spectrum to even out the procedural error, if any. The values of this ratio at different temperatures, when plotted against sample temperature, shows a break at Tc as confirmed by spin label ESR studies.

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