Y. Miura et T. Yamagata, GLYCOSYLATION OF LACTOSYLCERAMIDE ANALOGS IN ANIMAL-CELLS - AMPHIPATHIC DISACCHARIDE PRIMERS FOR GLYCOSPHINGOLIPID SYNTHESIS, Biochemical and biophysical research communications, 241(3), 1997, pp. 698-703
N-Acylaminoethyl lactosides as lactosylceramide analogs as well as n-a
lkyl lactosides were examined for their ability to prime glycosphingol
ipid (GSL) synthesis in mouse melanoma B16 cells. Using compounds radi
olabeled in a galactose residue and having nondegradable thioglucosidi
c Linkages in lactoside, direct glycosylation was shown to occur at th
e terminal galactose residue of lactosides subsequent to uptake by cel
ls and dissemination into Gels compartments. B16 cells took in lactosi
des temperature-dependently to the point of saturation. All lactosides
were taken up and glycosylated by B16 cells. C-8-lactosides could not
settle on the plasma membrane, while C-16-lactosides remained within
the cells. Glycosylation in all cases was cellular GSL-specific, sugge
sting the involvement of glycosyltransferases in GSL synthesis during
glycosylation of lactosides. The priming of GSL synthesis by lactoside
s inhibited the cell surface expression of endogenous GM(3) in B16 cel
ls. Lactosylceramide analogs are thus shown useful as primers for glyc
osylation and to modify GSL expression, and these features should faci
litate clarification of the functions of GSLs which have yet to be elu
cidated. (C) 1997 Academic Press.