Use of matrix clusters and trypsin autolysis fragments as mass calibrants in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
Trypsin autolysis fragments and matrix clusters are often observed as intense peaks in mass spectra of protein digests. It is demonstrated that these can be exploited to improve the mass calibration of a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectrometer. Interpretation of some of the autolysis masses is complicated by the existence of disulfide bonds. Surprisingly large matrix clusters are often visible for alpha-cyano-4-hydroxy-cinnamic acid. The fractional part of their masses differentiates them from protein digestion fragments.
Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
William A
WA
Harris
Dariusz J
DJ
Janecki
James P
JP
Reilly
D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D002138:Calibration; D002417:Cattle; D003373:Coumaric Acids / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry; D007202:Indicators and Reagents; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D014357:Trypsin / Q000737:chemistry*
D003373:Coumaric Acids; D006454:Hemoglobins; D007202:Indicators and Reagents; D010446:Peptide Fragments; C007175:alpha-cyano-4-hydroxycinnamate; D014357:Trypsin