The aqueous solution structure of the tetrasaccharide-ribitol repeat-unit from the lipoteichoic acid of Streptococcus pneumoniae strain R6 determined using a combination of NMR spectroscopy and computer calculations

Abstract High-resolution 1D- and 2D-correlation 1 H NMR and 13 C NMR, at 500 and 125 MHz, respectively, permitted assignment of the majority of the resonances in the per- N -acetylated, phosphorylated tetrasaccharide-ribitol repeat-unit, and in the complete polymer ( n = 5-7) containing between five and seven repeating units attached to the deacylated lipid anchor, for the lipoteichoic acid from Streptococcus pneumoniae strain R6; the 31 P resonances were also assigned. Comparison of the 31 P spectra obtained for the per- N -acetylated oligosaccharide and for the oligosaccharide having the AATG 4-NH 2 group still free, indicate a conformational difference brought about by interaction between the amino grop and the neighboring phosphate group.