Structure of type 3Gn coaggregation receptor polysaccharide from Streptococcus cristatus LS4

The presence of a novel coaggregation receptor polysaccharide (RPS) on the dental plaque isolate Streptococcus cristatus LS4 was suggested by this strain's antigenic and coaggregation properties. Examination of RPS isolated from strain LS4 by a combination of 2-dimensional and pseudo 3-dimensional single quantum heteronuclear NMR methods that included detection of C-13 chemical shifts at high resolution revealed the following repeat unit structure: -> 6)-beta-D-Galf-(1 -> 6)-beta-D-GalpNAc-(1 -> 3)-alpha-D-Galp-(1 -> P -> 6)-alpha-D-Galp-(1 -> 3)-beta-L-Rhap-(1 -> 4)-beta-D-Glcp-(1 ->. The identification of this polysaccharide as RPS3Gn, a new structural type, was established by the alpha-D-Galp-containing epitope of RPS serotype 3 and Gn recognition motif (i.e., beta-D-GalpNAc (1 -> 3)-alpha-D-Galp) for coaggregation with other bacteria. (C) 2011 Elsevier Ltd. All rights reserved.