Mass spectrometric analysis of lipo-chitin oligosaccharides-Signal molecules mediating the host-specific legume-rhizobium symbiosis

Applications of Electron−Ion Dissociation Reactions for Analysis of Polycationic Chitooligosaccharides in Fourier Transform Mass Spectrometry

“…Formation of the C 3 and C 4 ions during CAD of both singly and doubly protonated molecular species is apparently a favorable process. This process did not occur at all under high-energy collision conditions in sector instruments . But C n ions can be observed in HE CAD spectra .…”

“…The C 4 ion ( m / z 831), the highest mass member of the series, was observed only in low abundance. Thus, ECD caused cleavage of the doubly protonated (GlcNAc) 5 and resulted in many more nonreducing end fragments than in HE CAD of singly protonated analogues . In the latter, no formation of the C n /Y n ions was observed at all.…”

“…Lipotetraglucosamine (GlcN 4 - COCH 2 CHOHC 11 H 25 ) (3 ; Scheme ). Since the ChOSs studied so far are symmetric, an unambiguous identification of the B-/Z-type ions and the Y-/C-type ions cannot be done, even despite the assumption, based on the HE CAD study of protonated pentaChOS amide analogues …”

Sequence Analysis of Chitooligosaccharides by Matrix-Assisted Laser Desorption Ionization Postsource Decay Mass Spectrometry

“…If the reducing end is tagged by derivatization, clear-cut data are expected. In the case of AMAC a The automatic calibration routine selected the second peak (one 13 C atom in the molecule) from the isotopic peak pattern of the fragment instead of the monoisotopic peak ( 12 C only). Therefore, the measured m/z value was 1 Da higher (m + 1) than the calculated monoisotopic mass.…”

Root Nodulation and Infection Factors Produced by Rhizobial Bacteria

“…Competition experiments, which can be used to simulate the natural situation in soil, might show that various rhizobial factors whose inactivation leads to only minor phenotypes can be very important in symbiosis. Future studies on the role of glycans will also be greatly helped by the big advances in new technologies that will assist in the determination of complex carbohydrate structures or biochemical function of their biosynthetic enzymes, such as new mass spectrometry instrumentation (176) and better tools for protein crystallization studies. Perhaps the most important advance can be expected to come from the large-scale analyses of the genomes of several rhizobial species and related species from the α-proteobacteria group.…”