Figure 6.

A, negative-ion MALDI mass spectrum of intact LPS from S. fredii HH103 rkpA recorded in linear mode. Both LPS molecular ions and their ion fragments, attributable to the core OS (OS_A, OS_B) and lipid A (LipA) species, are visible and indicated in the spectrum. B, negative-ion MALDI mass spectrum of LPS of S. fredii HH103 mutant rkpM recorded in reflectron mode. The lipid A (LipA) and core OS (OS_A, OS_B, OS_C) species are also indicated in the spectrum. Proposed structural assessment of some LPS-related ions has been reported.