[The mechanism of action of aminoglycosides].

The mechanism of action of aminoglycosides depends on the inhibition of polypeptide synthesis. In fact, some of them such as Streptomycin, Sisomicin and Gentamicin are believed to cause codon misreading, by increasing the incorporation of certain aminoacids into polypeptide in the ribosome-polyribonucleotide system. Their primary site of action seems to be located in the bacterial ribosome system. Experiments with Sisomicin showed that this antibiotic arrest cell growth, aminoacid incorporation and Beta-galactosidase synthesis, but not incorporation of uracil in ribonucleic acid in E. coli cultures. When polypeptide synthesis is directed by endogenous messenger in cell-fre extracts, the antibiotic stimulates the incorporation of some amino acids into protein.