Original scientific paper

A Kinetic Study of the Inhibition of Protein Synthesis by Several Antibiotics

M. Protić ; Department of Organic Chemistry and Biochemistry »Ruaer Boskovic« Institute, Bijenicka 54, 41000 Zagreb, Croatia, Yugoslavia
Ž. Kućan ; Department of Organic Chemistry and Biochemistry »Ruaer Boskovic« Institute, Bijenicka 54, 41000 Zagreb, Croatia, Yugoslavia

Abstract

The effects of several antibiotics on the initial reaction rates
of the polyphenylalanine and polylysine syntheses were measured
in cell-free systems from Escherichia coli MRE600, stimulated by
polyuridilic and polyadenylic acid, respectively. lVIichaelis-Menten
··type of dependence on the tRNA concentration, and a sigmoidal
(possibly cooperative) dependence on the polynucleotide concentration
was obtained. Puromycin and chloramphenicol were competitive
inhibitors with respect to tRNA, while erythromycin,
streptomycin and chlorotetracycline were non-competitive inhibitors.
On the other hand, erythromycin was apparently a competitive
inhibitor with respect to the synthetic polynucleotide, while
other above-mentioned antibiotics showed either uncompetitive,
non-competitive or mixed type of inhibition. This kinetic approach
enabled the calculation of inhibition constants for the examined
antibiotics; they ranged from 2.5 x 10-7 mol dm·3 for erythromycin
and streptomycin, to over 1 · 10·4 mol dm-a for puromycin.

Keywords

Hrčak ID:

195867

URI

https://hrcak.srce.hr/195867

Publication date:

1.3.1980.

Visits: 678 *