MALDI-TOF MS analysis of acetylated xylans of the wild type and various mutants.

<p>DMSO-extracted xylans were digested with endoxylanase and subject to MALDI-TOF MS. The major ion peaks of masses are indicated and their xylooligomer structures are listed below. Xyl_n(GlcA)_n(Ac)_n denotes a xylooligomer (with n number of xylosyl residues) substituted with n number of GlcA and n number of acetyl groups. <i>m/z</i> 743, Xyl₅(Ac); <i>m/z</i> 745, Xyl₄(GlcA); <i>m/z</i> 759, Xyl₄(MeGlcA); <i>m/z</i> 787, Xyl₄(GlcA)(Ac); <i>m/z</i> 801, Xyl₄(MeGlcA)(Ac); <i>m/z</i> 817, Xyl₃(MeGlcA)₂; <i>m/z</i> 843, Xyl₄(MeGlcA)(Ac)₂; <i>m/z</i> 877, Xyl₅(GlcA); <i>m/z</i> 891, Xyl₅(MeGlcA); <i>m/z</i> 919, Xyl₅(GlcA)(Ac); <i>m/z</i> 975, Xyl₅(MeGlcA)(Ac)₂; <i>m/z</i> 1017, Xyl₅(MeGlcA)(Ac)₃; <i>m/z</i> 1051, Xyl₆(GlcA)(Ac); <i>m/z</i> 1065, Xyl₆(MeGlcA)(Ac); <i>m/z</i> 1093; Xyl₆(GlcA)(Ac)₂; <i>m/z</i> 1107; Xyl₆(MeGlcA)(Ac)₂; <i>m/z</i> 1123, Xyl₅(MeGlcA)₂(Ac); <i>m/z</i> 1135, Xyl₆(GlcA)(Ac)₃; <i>m/z</i> 1149, Xyl₆(MeGlcA)(Ac)₃; <i>m/z</i> 1165, Xyl₅(MeGlcA)₂(Ac)₂; <i>m/z</i> 1183, Xyl₇(GlcA)(Ac); <i>m/z</i> 1197, Xyl₇(MeGlcA)(Ac); <i>m/z</i> 1225, Xyl₇(GlcA)(Ac)₂; <i>m/z</i> 1241, Xyl₆(GlcA)(MeGlcA)(Ac); <i>m/z</i> 1267, Xyl₇(GlcA)(Ac)₃; <i>m/z</i> 1283, Xyl₆(GlcA)(MeGlcA)(Ac)₂; <i>m/z</i> 1357, Xyl₈(GlcA)(Ac)₂. Note the increase in the abundance of ions at <i>m/z</i> 745, 759, 877, and 891 (marked in red) corresponding to non-acetylated xylooligomers in <i>tbl32 tbl33</i>, <i>tbl32 esk1</i>, <i>tbl33 esk1</i>, and <i>tbl32 tbl33 esk1</i>.