High-performance size-exclusion chromatographic behaviour of substituted benzoylpoly-l-lysines by principal component analysis and molecular dynamics simulation

Conjugates containing benzoyl residues bound to poly-l-lysine (l-PLL) and l-lysine were prepared. The characterization was performed by UV spectrophotometry, 1H NMR, size-exclusion chromatography (HPSEC) and circular dichroism. The principal component analysis method was used in order to evaluate the relationships among the retention time in HPSEC and several parameters of the substrates. The results of this approach suggest that the set of experimental variables give different significant information. A molecular dynamics calculation of a model of these conjugates shows folding of the polypeptide backbone upon derivatization with the 4-methylbenzoyl group. Multivariate analysis and molecular dynamics simulations are important tools for the interpretation of the physicochemical characteristics (including those involved in separation science) of hapten-polypeptide and hapten-protein conjugates used in clinical chemistry and in biotechnology.