Hydrophilic properties as a new contribution for computer-aided identification of short peptides in complex mixtures.

A new method to predict elementary amino acid (AA) composition of peptides (molar mass <1,000 g/mol) is described. This procedure is based on a computer-aided method using three combined analyses-reversed phase liquid chromatography (RPLC), hydrophilic interaction chromatography (HILIC) and capillary electrophoresis coupled with mass spectrometry-and using a software calculating all possible amino acid combinations from the mass of any given peptide. The complementarity between HILIC and RPLC was demonstrated.

Modeling the separation of small peptides by cation-exchange chromatography.

Cation-exchange chromatography was applied for the separation of short synthetic peptide standards, with various charges and hydrophobicities. The methodology to develop simple, reproducible and accurate models, based on physicochemical peptide properties, was described. A multilinear regression method was used for the calculation of the models, and descriptors were chosen according to the observed phenomena.