Peptide and protein identification by matrix-assisted laser desorption ionization (MALDI) and MALDI-post-source decay time-of-flight mass spectrometry

The potential of matrix-assisted laser desorption ionization (MALDI) and MA LDI-post-source decay (PSD) time-of-flight mass spectrometry for the charac terization of peptides and proteins is discussed. Recent instrumental devel opments provide for levels of sensitivity and accuracy that make these tech niques major analytical tools for proteome analysis. New software developme nts employing protein database searches have greatly enhanced the fields of application of MALDI-PSD. Peptides and proteins can be easily identified e ven if only a partial sequence information is determined. Derivatization pr ocedures have been optimized for MALDI-PSD to increase the structural infor mation and to obtain a complete peptide sequence even in critical cases. Th ey are fast, simple and can be performed on target. MALDI-PSD is also a ver y powerful tool to characterize or elucidate post-translational or chemical ly induced modifications. Ln association with database searches, proteins i ssued from electrophoretic gels can be identified after specific enzymatic cleavages and peptide mapping. (J Am Soc Mass Spectrom 1999, 10, 91-103) (C ) 1999 American Society for Mass Spectrometry.