title: MALDI-TOF mass spectrometry of a combinatorial peptide library: effect of matrix composition on signal suppression.
abstract: The effect of matrix composition on signal suppression caused by a dominant compound under MALDI ionization was studied using the combinatorial TQTXT pentapeptide library as a model system. The peptide library is composed of 19 components with all proteinogenic amino acids except cysteine in position X. From these compounds, only the Arg peptide (TQTRT) was detected with sufficient intensity in the MALDI-TOF mass spectrum under typical MALDI conditions (CCA matrix). The analysis of a set of compounds utilized as different matrix components, additives and a cationizing agent revealed that the composition of the matrix is a critical point in signal suppression. Highly improved ion yields were achieved by using a CCA/DHB mixture as a matrix. The addition of K(+) as a cationizing agent to the CCA matrix resulted in MALDI-TOF mass spectra with relative ion intensities very similar to those obtained by electrospray ionization.
authors.affiliation: Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös L. University, P. O. Box 32, Budapest 112, Hungary, H-1518.
authors.forename: Gitta
authors.initials: G
authors.lastname: Schlosser
authors.forename: Gabriella
authors.initials: G
authors.lastname: Pocsfalvi
authors.forename: Emoke
authors.initials: E
authors.lastname: Huszár
authors.forename: Antonio
authors.initials: A
authors.lastname: Malorni
authors.forename: Ferenc
authors.initials: F
authors.lastname: Hudecz
mesh_terms: D020650:Combinatorial Chemistry Techniques; D009842:Oligopeptides / Q000737:chemistry*; D019151:Peptide Library; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D009842:Oligopeptides; D019151:Peptide Library