Structure of Escherichia coli capsular antigen K34

The structure of the heat-stable K antigen of Escherichia coli serotype K34 has been determined by n.m.r. spectroscopy, methylation analysis, and Smith degradation to be (formula; see text) The assignment of the single alpha-linkage to the D-glucosyl residue was confirmed by the positive reaction of an alpha-D-glucosidase on the oligosaccharide obtained by bacteriophage depolymerization. It is noteworthy that the same enzyme was without action on the native polysaccharide.