Fig. 12.

Live S. pyogenes cells make HA with a chitin oligo at the NR-end. Native HA (Lifecore, 730 kDa), of the original size made by fermentation, was digested extensively with lyase and fractionated as in Figure 2 and Methods; ACN fractions are shown. (A) MALDI-TOF MS in negative mode, shows m/z signals for four G₄H_n species at 1587.4577 (G₄H₂), 1966.5301 (G₄H₃), 2345.6168 (G₄H₄) and 2724.7179 (G₄H₅). (B) PSD analysis of the m/z 1966 parent M⁻¹ ion shows five breakdown fragments (indicated by labels) expected for this chitin-HA oligo structure. Table V summarizes results from multiple PSD analyses of the m/z 1587, 1966 and 2345 M⁻¹ species.