Fig 6.
MALDI-TOF mass spectrometry of SCWP isolated from wild-type and patA1 patA2 mutant B. anthracis strains. (A) rpHPLC-purified SCWP from wild-type B. anthracis was subjected to MALDI-TOF mass spectrometry, and ion spectra were recorded. m/z, mass-to-charge ratio. The ion signal marked with an asterisk (*) identifies the sodiated adduct of a compound with the predicted structure [β-ManNAc-(1→4)-β-GlcNAc(Gal)-(1→6)-α-GlcNAc(Gal)2]. (B) rpHPLC-purified SCWP from patA1 patA2 mutant B. anthracis was analyzed by MALDI-TOF mass spectrometry, and ion spectra were recorded. (C) The SCWP is comprised of the repeating unit [→4)-β-ManNAc-(1→4)-β-GlcNAc-(1→6)-α-GlcNAc-(1→]n (printed in black), where α-GlcNAc is replaced with α-Gal and β-Gal at O-3 and O-4, respectively, and the β-GlcNAc is replaced with α-Gal at O-3 (galactosyl substitutions printed in blue) (16).