Determination of binding constants between the antibiotic ristocetin A and D-Ala-D-Ala terminus peptides by affinity capillary electrophoresis

Abstract

SummaryBinding constants belween the antibiotic ristocetin A (Rist A) and D-Ala-D-Ala terminus peptides were determined using affinity capillary electrophoresis (ACE). In these experiments ~o techniques are used to obtain binding constants. In the first, a plug of RistAand non-interacting standards are injected and electrophoresed. Analysis of the change in the relative migration time ratio (RMTR) of Rist, relative to the non-interacting standards, as a function of the concentration of peptide, yields a value for the binding constant (Kb). In the second, samples of peptide and standards are injected and electrophoresed in increasing concentrations of Rist A in the running buffer. Analysis using the RMTRyields a Kb. The findings described here demonstrate the advantage of using ACE for estimating binding parameters be~een antibiotics and ligands.

Estimation of binding constants between ristocetin and teicoplanin and peptides using on-column ligand derivatization coupled to affinity capillary electrophoresis

“…Table 1 summarizes the binding data obtained for the binding of glycopeptides to D-Ala-D-Ala terminus peptides. The values for K b obtained by the oncolumn ligand derivatization technique are comparable to those observed using standard ACE techniques [16,19].…”

“…During the past decade affinity capillary electrophoresis (ACE) has emerged as a useful and sensitive technique for studying bimolecular noncovalent interactions and for determining binding and dissociation constants of formed complexes [15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32]. ACE uses the resolving power of CE to distinguish between the free and bound forms of a receptor as a function of the concentration of free ligand.…”

Recent advances in capillary electrophoresis and capillary electrochromatography of peptides

“…In this technique, four separate plugs of sample are introduced into the capillary and electrophoresed. [106], ristocetin A [107], and their on-column modified derivatives [56]. Several other applications of CAE for the investigation of the interactions of glycopeptide antibiotics, vancomycin, ristocetin and their derivatives, with peptides that mimic the bacterial cell wall binding site can be found in the survey [108].…”

“…CAE is now widely used for the determination of association or dissociation constants of peptide complexes with both low-and high-molecular-mass ligands. Several studies have been performed to estimate receptor-ligand interactions using a model system consisting of glycopeptide macrocyclic antibiotic vancomycin from Streptomyces orientalis and free or derivatized dipeptide D-Ala-D-Ala [55,106,107]. CE techniques are frequently applied to the quantitative investigation of peptide interactions with other peptides, proteins, nucleic acids or other ligands.…”

Chromatography of amino acids and short peptides. New advances

“…Calculations indicated that the binding constants of peptides show considerable differences. The affinity CE method has been proposed for the determination of other molecular interactions (Azad et al, 2003).…”