High-performance liquid chromatography of amino acids, peptides and proteins. CXXII. Application of experimentally derived retention coefficients to the prediction of peptide retention times: studies with myohemerythrin.

Amino acid retention coefficients were derived from the experimental retention data of 118 overlapping peptide heptamers related to the primary amino acid sequence of myohemerythrin. Individual retention coefficient values for each amino acid were derived by a multiple linear regression matrix approach. Retention data were derived for five different experimental conditions including different organic modifiers (acetonitrile, methanol or 2-propanol), different mobile phase additives (trifluoroacetic acid or potassium phosphate) and different silica-based stationary phase ligands (octadecyl or phenyl groups). A high degree of correlation was observed between these experimentally derived amino acid coefficients (EXP) and the coefficients (LIT) which we recently reported derived from the retention data of over 2000 peptides [M. C. J. Wilce et al., J. Chromatogr., 536 (1991) 165 and 548 (1991) 105]. These results demonstrated that the LIT and EXP coefficients can be used for the prediction of the retention of any peptide set. The effect of peptide length was also further investigated and the correlation results demonstrated the importance of peptide flexibility on the final value of the amino acid coefficient.