Fig. 7.

Partial 600-MHz NMR spectra indicating the linkage of pyruvate to the terminal ManNAc residue in Ba684 SCWP. (A) ¹H–¹³C HSQC; (B) ¹H–¹³C HMBC; (C and D) HMBC spectra of the pyruvate spin system. The spectra are shown at high intensity to allow the visualization of this structural modification, which occurs at one location in the SCWP. Favorable bond geometry and magnetic environment yield coupling between PyrC2 and one of the B′H6 protons. Circled moieties on B′, C′ and A′ highlight the substoichiometric structural modifications, and circled positions on B, C and A indicate the position of galactosylation in the B. anthracis Sterne, Pasteur and Ames SCWPs.