EXISTENCE OF NOVEL BRANCHED SIDE-CHAINS CONTAINING BETA-1,2 AND ALPHA-1,6 LINKAGES CORRESPONDING TO ANTIGENIC FACTOR-9 IN THE MANNAN OF CANDIDA-GUILLIERMONDII

Isolation of beta-linkage-containing side chain oligosaccharides from the mannan of Candida gilliermondii IFO 10279 strain has been conducte d by acetolysis under mild conditions, A structural study of these oli gosaccharides by one- and two-dimensional NMR and methylation analyses indicated the presence of extended oligosaccharide side chains with t wo consecutive beta-1,2-linked mannose units at the nonreducing termin al of alpha-linked oligosaccharides, The linkage sequence present in t his mannan, Man beta 1-->2Man alpha 1-->3Man alpha-->, has also been f ound in the mannan of Saccharomyces kluyveri but not in the mannan of Candida species, Furthermore, these oligosaccharides are branched at p osition 6 of the 3-O-substituted mannose units as follows. [GRAPHICS] The H-1 signals of the mannose units substituted by a 3,6-di-O-substit uted unit showed a significant upfield shift (Delta delta = 0.04-0.08 ppm) due to a steric effect, The inhibition of an enzyme linked immuno sorbent assay between the mannan of C. guilliermondii and factor 9 ser um with oligosaccharides obtained from several mannans indicated that only the oligosaccharides with the above structure were active, sugges ting that these correspond to the epitope of antigenic factor 9.