On the tryptic peptide features providing their detection and identification by MALDI mass spectrometry


B.L. Milman1, А.V. Solov’eva, N.V. Lugovkina, I.K. Zhurkovich

The tryptic peptide features providing detection and identification of these bio compounds and corresponding proteins by matrix-assisted laser desorption/ionization mass spectrometry (MALDI) with the α-cyano-4-hydroxycinnamic acid matrix, are determined and discussed. Twenty five proteins were identified; the features of reliably identified peptides are compared to those of peptides which might be produced by tryptic cleavage and were not detected. Two key factors enhancing a detection possibility of tryptic peptides, were determined. The first one refers to the gas-phase peptide basicity, which is the highest for the C-terminal end arginine peptides; this reason for the emergence of big analytical signals is well-known. The second factor providing ionization of peptides under consideration in the MALDI conditions is their hydrophility. This result does not correlate with the most conclusions of earlier relevant researches and discussed in the article.

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