Stability of carbohydrate-modified vesicles in vivo: comparative effects of ceramide and cholesterol glycoconjugates.

The stability and tissue distribution of lipid vesicles modified at the surface by the incorporation of either a galactosyl ceramide (GalCer) or a galactosyl cholesterol (GalChol) glycoconjugate have been studied in mice by measuring the release of vesicle-entrapped 111In. Although the tissue distributions of both vesicle types were similar, the GalCer-containing vesicles were markedly less stable than those prepared with GalChol, whether administered orally or by intraperitoneal injection. Physical characterization of the vesicles in vitro suggests that the increased disruption rate for GalCer vesicles in vivo is related to structural instabilities induced by the cerebroside, which can then result in either an increased rate of vesicle uptake by tissues or a greater susceptibility to lysis.

Lipid-associated chlorophyll: evidence from 13C-NMR of the photosynthetic spinach thylakoid membrane.

The 13C-NMR spectrum at 90.5 MHz has been obtained for the photosynthetic thylakoid membrane of spinach. Specific lipid and chlorophyll resonances can be assigned in the high resolution spectrum, although protein resonances are not observed.