Post-source decay fragmentation

T. Yamagaki, Y. Mitsuishi, H. Nakanishi. Post-source decay fragment analysis of a highly branched nonasaccharide of xyloglucan using M ALDI-TOF mass spectrometry. Chem. Lett. 1998,57-58. 

T. Yamagaki, Y. Ishizuka, S.-I. Kawahara, H. Nakanishi. Analysis of glycosidic linkages in saccharide compounds by post-source decay fragment methods in matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. Rap. Comm. Mass. Spec. 1999, /1,527-531. 

PrzybUla, L., Rader, H.J., and Mullen, K., Post source decay Fragment Ion Analysis of polycarbonates by MALDI-TOF, Europ. Mass Spectrom, 5,133 (1999). 

Laine, O., Trimpin, S., Raeder, H.J., and Muellen, K. (2003) Changes in post-source decay fragmentation behavior of poly(methyl methacrylate) polymers with increasing molecular weight studied by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Eur. J. Mass Spectrom., 9, 195-201. 

Lattova, E. Perreault, H. Krokmn, O. Matrix-assisted laser desorption/ionization tandem mass spectrometry and post-source decay fragmentation study of phenylhydrazones of N-linked oligosaccharides from ovalbumin. J. Am. Soc. Mass Spectrom. 2004, 15, 725-735. 

Experimentation showed that the protein was not glycosylated and that the sequence at the iV-amino acid terminus corresponded to that expected. The C-terminus sequence, however, did not correspond to that predicted and these data were interpreted in terms of the presence of a heterogeneous, truncated, protein. A study of the tryptic digest fragments from this protein with matrix-assisted laser desorption ionization (MALDI) with post-source decay enabled the authors to suggest the positions at which the parent protein had been truncated. 

Several original papers must be mentioned that deal with mass spectrometric techniques which the numerous reviews do not comprise. Kaufmann and coworkers268,288 studied the mass spectrometric analysis of carotenoids and some of their fatty acid esters using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry and its post-source-decay (PSD) variant. Some advantages concerning the thermal instability and limited solubility were discussed, but the fragmentation paths of the carotenoid cations were found to be essentially the same as those observed with conventional techniques. 

Note In particular the MALDI-TOF community has coined some sort of an own terminology, e.g., in-source decay (ISD) for all fragmentations occurring within the ion source, post-source decay (PSD) instead of metastable ion dissociation and fragment analysis and structural TOF (FAST) for the specific mode of operation of a ReTOF to detect metastable ions. 

Keki, S., Deak, G., and Zsuga, M., Fragmentation study of rutin, a naturally occurring flavone glycoside cationized with different alkali metal ions, using post-source decay matrix-assisted laser desorption/ionization mass spectrometry, J. Mass Spectrom., 36, 1312, 2001. 

Because the soft ionization methods used for oligosaccharides produce few fragments, collision-induced dissociation (CID) or post-source decay (PSD) must be used for structural study. These two techniques have been applied to deprotonated, protonated or alkaliated... 

We have implemented scanning methodologies using MALDI-TOF mass spectrometry to partially purified venom from C. striatus and C. ermineus. We have carried out specific derivatizations in order to deduce composition and sequence information. Together with an intact mass these measurements are used to determine whether an ionized species observed in the MALDI mass spectrum corresponds with the intact protonated molecule of a previously characterized conotoxin. The information obtained from derivatizations is also important when the ionized species does not correspond with the intact mass of peptides of known sequence. In that case, post source decay of the native and derivatized species may help assign the fragment ions. 

Recently, fragmentations by post source decay (PSD) was introduced as a technique to obtain structural information in MALDI MS [6,7]. We describe here the combined use of automated Edman sequencing and MALDI sequencing for the determination of proteolytic peptide fragments in the low picomole range. 

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