TY - JOUR
T1 - Metastable decay of peptides and proteins in matrix‐assisted laser‐desorption mass spectrometry
AU - Spengler, Bernhard
AU - Kirsch, Dieter
AU - Kaufmann, Raimund
AU - Cotter, R. J.
PY - 1991/4
Y1 - 1991/4
N2 - Fragmentation of protein and peptide ions generated by matrix‐assisted laser desorption has been investigated using a modified LAMMA 1000 reflecting time‐of‐flight (TOF) mass spectrometer. Whereas fragmentation of covalent bonds prior to ion acceleration (i.e., within several ns after the laser pulse) in general is not observed using the matrix technique, extensive fragmentation on a longer time scale can be studied in our instrument. The high mass resolution (M/ΔM≈1200–1800 for insulin and peptides) permits the investigation of even small mass losses from parent molecular ions (occuring in the first section of the field‐free drift region) by measuring flight time differences of daughter ions acquired during passage through a two‐stage reflection. The kind and extent of this metastable decay has been found to depend strongly on the substance under investigation. Typical fragmentations are loss of ammonia and parts of the amino acid side‐chains. The large abundances of peaks due to such metastable fragmentation, observed for most of the peptides and proteins investigated, may, at least in part, explain peak broadening (and, hence, poor mass resolution) typical in matrix‐assisted laser‐desorption TOF mass spectra.
AB - Fragmentation of protein and peptide ions generated by matrix‐assisted laser desorption has been investigated using a modified LAMMA 1000 reflecting time‐of‐flight (TOF) mass spectrometer. Whereas fragmentation of covalent bonds prior to ion acceleration (i.e., within several ns after the laser pulse) in general is not observed using the matrix technique, extensive fragmentation on a longer time scale can be studied in our instrument. The high mass resolution (M/ΔM≈1200–1800 for insulin and peptides) permits the investigation of even small mass losses from parent molecular ions (occuring in the first section of the field‐free drift region) by measuring flight time differences of daughter ions acquired during passage through a two‐stage reflection. The kind and extent of this metastable decay has been found to depend strongly on the substance under investigation. Typical fragmentations are loss of ammonia and parts of the amino acid side‐chains. The large abundances of peaks due to such metastable fragmentation, observed for most of the peptides and proteins investigated, may, at least in part, explain peak broadening (and, hence, poor mass resolution) typical in matrix‐assisted laser‐desorption TOF mass spectra.
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U2 - 10.1002/rcm.1290050412
DO - 10.1002/rcm.1290050412
M3 - Article
AN - SCOPUS:84990652333
SN - 0951-4198
VL - 5
SP - 198
EP - 202
JO - Rapid Communications in Mass Spectrometry
JF - Rapid Communications in Mass Spectrometry
IS - 4
ER -