Binding of dipeptides and amino acids to Teicoplanin chiral stationary phase: apparent homogeneity of some heterogeneous systems

Anal Chem. 2009 Aug 15;81(16):6735-43. doi: 10.1021/ac900677f.

Abstract

The binding between Teicoplanin glycopeptide antibiotic and some dipeptides and amino acids has been studied by nonlinear liquid chromatography. A Teicoplanin-based chiral stationary phase, specifically designed to achieve maximum selectivity and loading by reducing non-specific interactions, has been prepared and packed into a microbore column. The adsorption isotherms of the enantiomers of proline, alanine, and alanine-alanine (Ala-Ala) have been measured through frontal analysis. The experimental binding data have been interpreted in the context of the ordinary homogeneous Michaelis-Menten model and by considering an heterogeneous model that accounts for a broad adsorption energy distribution (AED). AED has been achieved by the analysis of adsorption isotherms. Besides confirming the importance of the terminal D-Ala-D-Ala moiety in the molecular recognition between the dipeptide and the macrocyclic antibiotic Teicoplanin (it was found that Teicoplanin behaves as a molecular filter toward the enantiomers of Ala-Ala), this study shows that a heterogeneous adsorption model is needed for the correct interpretation of binding data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Amino Acids / chemistry*
  • Chromatography, Liquid / methods
  • Dipeptides / chemistry*
  • Kinetics
  • Models, Theoretical
  • Stereoisomerism
  • Teicoplanin / chemistry*
  • Thermodynamics

Substances

  • Amino Acids
  • Dipeptides
  • Teicoplanin