FIGURE 2.

A, MALDI-TOF mass spectrum of predominantly nongalactosaminylated arabinans (after acetylation) released by endogenous arabinase from the cell wall core (mAGP) of M. leprae. Both M + Na⁺ and, at 16 atomic mass units higher, M + K⁺ ions are seen. The major species released are Ara₇, Ara₁₈, and Ara₁₉ that are formed as illustrated in B. C, expansion of the spectrum from m/z 3900 to m/z 4500 showing the presence of 1–3 succinyl groups on Ara₁₈ and Ara₁₉. Also seen are the galactosaminylated arabinans for Ara₁₈ and Ara₁₉ as the galactosaminylated and nongalactosaminylated arabinans were not perfectly separated from each other.