Characteristics of the binding of aminoglycoside antibiotics to teichoic acids: A potential model system for interaction of aminoglycosides with polyanions

Abstract

The binding of the aminoglycoside antibiotic dihydrostreptomycin to defined cell‐wall teichoic acids and to lipoteichoic acid isolated from various gram‐positive eubacteria was follwed by equilibrium dialysis. Dihydro‐streptomycin was used at a wide range of concentration under different conditions of ionic strength, concentration of teichoic acid, presence of cationic molecules like Mg2+, spermidine, other aminoglycoside antibiotics (gentamicin, neomycin, paromomycin). Interaction of dihydrostreptomycin with teichoic acid was found to be a cooperaive binding process. The binding characteristics seem to be dependent on structural features of teichoic acid and are influenced by cationic molecules. Mg2+, spermidine and other aminoglycoside antibiotics inhibit the binding of dihydrostreptomycin to teichoic acid competitively. The binding of aminoglycosides to teichoic acids is considered as a model system for the interaction of aminoglycoside antibiotics with cellular polyanions. Conclusions of physiological significance are drawn. Copyright © 1985, Wiley Blackwell. All rights reserved