ISOLATION AND CHARACTERIZATION OF DOLICHOL-LINKED OLIGOSACCHARIDES FROM HALOFERAX-VOLCANII

Biosynthesis of procaryotic glycoproteins has been studied in some det ail only in the extreme halophile Halobacterium halobium. To extend th ese studies for a moderate halophile, dolichol phosphate-linked oligos accharides were isolated and characterized from Haloferax volcanii, Ma nnosyl (beta 1-->4)galactosyl phosphodolichol could be characterized a s a main component by GC/MS permethylation analysis, mass spectrometry and H-1-NMR-spectroscopy, Furthermore, two additional components, pre sent in lower quantities, were partially characterized and identified as a tetrasaccharyl phosphodolichol containing mannose, galactose, and rhamnose in the ratio of 2:1:1 as well as another dihexosyl phosphodo lichol. Both the latter compounds contain an additional charged group, All these oligosaccharides were found to be linked to a dolichol cons isting of 11 or 12 isoprene units including a saturated omega-terminal isoprene residue.