Matrix post source decay

Matrix-assisted laser desorption ionization post-source-decay mass spectrometry... 

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. 

B. Spengler. Post-Source Decay Analysis in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry of Biomolecules. J. Mass Spectrom., 32(1997) 1019-1036. 

The development glycopeptide libraries obtained by the split-mix method is severely hampered by the lack of concurrent development of a general, facile separation and characterization technology. Some headway has been made with chemical coding of the libraries, but very few direct methods of analysis exist. One promising method that could be applied to the direct characterization of both types of libraries is mass spectrometry. More specifically, post-source-decay matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (PSD-MALDI-TOF-MS) and CID-FAB/MS/MS have been used to characterize glycopeptides.53-55... 

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. 

Spengler B (2001) The basics of matrix-assisted laser desorption ionization time-of flight mass spectrometry and post source decay. In James P (ed) (2001) Proteome research Mass spectrometry. Springer, New York, p 33... 

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. 

Kaufmann, R., Wingerath, T., Kirsch, D., Stahl, W., and Sies, H. 1996. Analysis of carotenoids and carotenol fatty acid esters by matrix-assisted laser desorption ionization (MALDI) and MALDI-post-source-decay mass spectrometry. Anal. Biochem. 238 117-128. 

Spengler, B. (1 997) Post-source decay analysis in matrix-assisted laser desorption/ionization mass spectrometry of biomolecules. Journal of Mass Spectrometry 32, 1019-1036. 

B. Spengler, D. Kirsch, R. Kaufmann, and J. Lemoine, Structure analysis of branched oligosaccharides using post-source decay in matrix-assisted laser desorption ionization mass spectrometry, Org. Mass Spectrom., 29 (1994) 782-787. 

Kaufmann R, Chaurand P, Kirsch D, Spengler B. Post-source decay and delayed extraction in matrix-assisted laser desorption/ionization-reflectron time-of-flight mass spectrometry. Are there trade-offs . Rapid Commun Mass Spectrom 1996 10 1199-1208. 

Kaufmann, R., Kirsch, D., and Spengler, B. (1994). Sequencing of peptides in a time-of flight mass spectrometer Evaluation of post source decay following matrix-assisted laser desorption ionization (MALDI). Int. ]. Mass. Spectrom. Ion Processes 131, 355-385. 

With the advent of very sensitive ionization techniques such as matrix assisted laser desorption (MALDI) coupled with time-of-flight (TOF) mass analysis, measurement of the intact mass of peptides at sub-pmol levels has become a reality (2) of which we have taken advantage for the systematic screening of HPLC fractions. Partial sequence information can be obtained by carrying out enzymatic hydrolysis with exoproteinases (e.g. carboxypeptidases and aminopeptidases) (3, 4). More recently, MALDI has been used to measure metastable decomposition occurring in the first field free region of a reflectron TOF instrument (referred to as post source decay (PSD)) with only marginally more sample (5-7). 

In this study, we used matrix-assisted laser desorption ionization /Mass Spectrometry (MALDI/MS) to identify the peptides released from gastric parietal cell microsomes. MALDI, because of its sensitivity and relative tolerance to the presence of salts and buffers was examined for the analysis of unfractionated proteolytic digests (9, 10). MALDI with post-source decay (PSD) analysis was used to obtain sequence information on peptides even in crude digestion mixtures. Our strategy (Figure 1) consisted of proteolysis of intact vesicles, centrifugation at high speeds to separate membrane bound and soluble fractions and analysis of the mixture of released peptides by MALDI/MS. In addition, to increase the... 

T Pfeifer, M Drewello, A Schierhorn. Using a matrix-assisted laser desorp-tion/ionization time-of-flight mass spectrometer for combined in-source decay/post-source decay experiments. J Mass Spectrom 34 644—650, 1999. 

S. Goletz, M. Leuck, P. Franke, U. Karsten. Structure analysis of acelylated and non-acetylated O-linked MUCl-glycopeptides by post-source decay matrix-assisted laser desorption/ionization mass spectrometry. Rapid Commun. Mass Spectr. 1997,11, 1387-1398. 

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. 

Al-Saad, K.A., Siems, W.F., Hill, H.H., Zabrouskov, V. and Knowles, N.R., Structural analysis of phosphatidylcholines by post-source decay matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry, J Am Soc Mass Spectrom, 14 (2003a) 373-382. 

Figure 5. Methods employed for identifiying and characterizing proteins separated by 2DE. Abbreviations used 2DE, two-dimensional electrophoresis ESI, electrospray ionization HPLC, high performance liquid chromatography IR, infrared M, relative molecular mass MALDI, matrix-assisted laser desorption ionization MS, mass spectrometry MS/MS tandem mass spectrometry p/, isoelectric point PSD, post-source decay.

Kaufmann, R., Kirsch, D., Tourmann, J. L., Machold, J., Hucho, R, Utkin, Y., and Tsetlin, V, Matrix-Assisted Laser Desorption Ionization (MALDI) and Post Source Decay (PSD) Product Ion Mass Analysis Localize a Photolabel Crosslinked to the Delta-Subunit of Nachr Protein by Neurotoxin II, Eur. Mass Spectrom., 1, 313, 1995. 

Garozzo, D., Nasello, V., Spina, E., and Sturiale, L., Discrimination of Isomeric Oligosaccharides and Sequencing of Unknowns by Post Source Decay Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry, Rapid Comm. Mass. Spectrom., 11, 1561, 1997. 

Przybilla, L., Rader, H.-J, and Mullen, K., Post-source Decay Fragment Ion Analysis of Polycarbonates by Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry, Eur. Mass Spectrom., 5, 133, 1999. 

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