Preparation and comparison of model bilayer systems from chloroplasts thylakoid membrane lipids for 13C-NMR studies

Model bilayer systems from individual purified chloroplast thylakoid membrane lipids, from reconstituted mixtures of these purified lipids, and from leaf total polar lipid extracts have been prepared in water, and the longitudinal relaxation times (T1's) of the individual carbon atoms of the fatty acyl chains measured by 13C-NMR spectroscopy. The T1's increase with increasing distance of the carbon atoms from the polar headgroups in all cases, and as the results from each of the preparations are similar, all can be used as models of chloroplast membrane bilayers. Relaxation time measurements on intact chloroplast thylakoid membranes indicate the presence of chlorophyll resonances in the 13C-NMR spectrum of the membrane.