A quantitative peptide structurevs.retention relationship study (original) (raw)
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Acta Scientiarum Polonorum, Technologia Alimentaria
Background. Peptides are important components of foods mainly due to their biological activity. The basic method of their identification is reversed phase high-performance liquid chromatography coupled with electrospray-ionization mass spectrometry (RP-HPLC--ESI-MS). Retention time (tR) prediction in silico is very helpful in analysis of multicomponent peptide mixtures. One of problems associated with RP-HPLC-ESI-MS is deterioration of mass spectra quality by trifluoroacetic acid (TFA). This problem can be avoided through the use of chromatographic columns designed for work with low TFA concentrations in mobile phase. The objective of this study was to determine the correlations between peptide retention times predicted with the use of a program available on-line and experimental retention times obtained using the column working with low TFA concentrations. Material and methods. The set of synthetic peptides and bovine α-lactalbumin fragments (18 peptides) was used in the experiment...
Journal of chromatography. A, 2018
A model that predicts retention for peptides using a HALO penta-HILIC column and gradient elution was created. Coefficients for each amino acid were derived using linear regression analysis and these coefficients can be summed to predict the retention of peptides. This model has a high correlation between experimental and predicted retention times (0.946), which is on par with previous RP and HILIC models. External validation of the model was performed using a set of H. pylori samples on the same LC-MS system used to create the model, and the deviation from actual to predicted times was low. Apart from amino acid composition, length and location of amino acid residues on a peptide were examined and two site-specific corrections for hydrophobic residues at the N-terminus as well as hydrophobic residues one spot over from the N-terminus were created.
Journal of Chromatography A, 2009
We investigated the mechanisms involved in the retention of various peptides on a stationary phase embedded with a quaternary ammonium group (BS C23), by high-performance liquid chromatography. This was compared with peptide retention on a conventional reversed-phase C18 (RP C18) column under isocratic conditions, to understand better the various mechanisms involved. Chromatographic characterization of the two stationary phases with "model" compounds showed that BS C23 is less hydrophobic than RP C18 and induces electrostatic interaction (attraction or repulsion) with ionized compounds. If reversed-phase partitioning was the predominant retention phenomenon, for both stationary phases, the retention mechanisms in BS C23 provided different selectivity to that of RP C18. Electrostatic attraction or repulsion was clearly observed between peptides and the permanent positively charged group embedded in BS C23 depending on the pH. For most of the peptides, a weak anion-exchange mechanism was observed on the quaternary ammonium-embedded stationary phase if mobile phases at neutral pH and low ionic strengths were employed.