Protein synthesis inhibitors: tetracyclines mechanism of action animation. Classification of agents

Author
Gary Kaiser
Biology Department
The Community College of Baltimore County, Catonsville Campus
Baltimore, MD 21228
USA
Email: gkaiser@ccbcmd.edu

From Richard Harvey (series editor), Lippincott’s Illustrated Reviews: Pharmacology (LWW, 2008):

” Tetracyclines

The tetracyclines are a group of closely related compounds that, as the name implies, consist of four fused rings with a system of conjugated double bonds. Substitutions on these rings are responsible for variation in the drugs’ individual pharmacokinetics, which cause small differences in their clinical efficacy.

Mechanism of action

Entry of these agents into susceptible organisms is mediated both by passive diffusion and by an energy-dependent transport protein mechanism unique to the bacterial inner cytoplasmic membrane. Nonresistant strains concentrate the tetracyclines intracellularly. The drug binds reversibly to the 30S subunit of the bacterial ribosome, thereby blocking access of the amino acyl-tRNA to the mRNA-ribosome complex at the acceptor site. By this mechanism, bacterial protein synthesis is inhibited”

Tetracyclines classification according to source

Naturally-occurring
- Tetracycline (Ala-Tet, Brodspec, Panmycin, Sumycin, Tetracon)
- Chlortetracycline
- Oxytetracycline
- Demeclocycline (Declomycin)
Semi-synthetic
- Doxycycline (Adoxa, Atridox, Doryx, Monodox, Vibramycin)
- Lymecycline
- Meclocycline
- Methacycline
- Minocycline (Arestin, Dynacin, Minocin, Vectrin)
- Rolitetracycline

Tigecycline may also be considered a tetracycline antibiotic, though it is usually classified as a glycylcycline antibiotic.

Further reading