Sequence analysis of chitooligosaccharides by matrix-assisted laser desorption ionization postsource decay mass spectrometry.
Chitin/chitosan oligosaccharides composed of 2-acetamido-2-deoxy-D-glucopyranose (GlcNAc) and/or 2-amino-2-deoxy-D-glucopyranose (GlcN) were prepared by chemical degradation of chitin or chitosan and separated by gel permeation chromatography. Oligosaccharides obtained after enzymatic hydrolysis of chitosan [F(A) 0.19] with a fungal chitinase were derivatized by reductive amination with 2-aminoacridone and sequenced by matrix-assisted laser desorption ionization time-of-flight postsource decay (PSD) mass spectrometry (MS). The sequence of a trimer, D1A2, was established as D-A-A. The composition of a hexamer D3A3 was ca. 65% D-A-D-D-A-A and 35% D-D-A-D-A-A. The PSD MS of a nonamer D5A4-amac revealed four isobaric species D-X-Y-D-X-Y-D-A-A, where A is GlcNAc, D is GlcN, and X and Y (X not equal Y) are mutually either D or A. This structure motif was also observed in a dodecamer D7A5 which was composed of eight isobaric sequences of the general formula (D-X-Y)(3)-D-A-A.
Bahrke
Sven
S
Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 25, D-14476 Golm, Germany.
Einarsson
Jon M
JM
Gislason
Johannes
J
Haebel
Sophie
S
Letzel
Matthias C
MC
Peter-Katalinić
Jasna
J
Peter
Martin G
MG
D000818:Animals; D002240:Carbohydrate Sequence; D002686:Chitin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D048271:Chitosan; D003445:Crustacea / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D017421:Sequence Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D009844:Oligosaccharides; D002686:Chitin; D048271:Chitosan