Structural studies on the amino-acid-linked teichuronic acid of Bacillus subtilis AHU 1219 cell walls.

Structural studies were carried out on a teichuronic acid isolated from a mild acid extract of Bacillus subtilis AHU 1219 cell walls. The teichuronic acid contained D-glucuronic acid, D-glucose, D-galactose, L-serine and L-threonine in a molar ratio of 1:1:1:0.5:0.5. Results of analyses of the polysaccharide by Smith degradation, methylation and 1H-NMR and 13C-NMR spectroscopy, in combination with data on analyses of oligosaccharides obtained by partial acid hydrolysis and alkaline hydrolysis of the polymer, led to the most likely structure for the repeating unit, ----4)(L-Ser/L-Thr)-D-GlcA(beta 1----3)-D-Glc(beta 1----4)-D-Gal(alpha 1----. In each unit, either amino acid is linked to the glucuronic acid residue through an amide bond.