Structure of the D-glucans produced by Neisseria perflava

A chemical and enzymic study of the cellular glucan of Neisseria perflava and of the glucan produced from sucrose by a cell-free extract of N. perflava showed from optical rotation, 13C nuclear magnetic resonance, methylation analysis, and alpha- and beta-amylase hydrolysis studies that the glucans had glycogen-like structures. These structures were composed of chains of 1-4-alpha-D-glucopyranosyl units with branch points of 4-O- and 6-O-disubstituted D-glucopyranose units. While the backbone structures of the two glucans were similar, the release of maltose by the action of beta-amylase indicated that the 1-4 linked nonreducing side chains of the cell-free enzymically synthesized glucan were longer (approximately seven units) than those present in the cellular glucan (approximately two to three units), a result in agreement with methylation analyses.