Protein synthesis inhibitors specific agents

The uncoating process has been shown to be carried out by virus-specific enzymes, synthesized at the direction of viral mRNA. The mRNA in turn has used a portion of the viral DNA as the template. Experimentally, at least, protein synthesis inhibitors can inhibit the production of these uncoating enzymes. However, due to a lack of significant specificity, the compounds were of no clinical value. The antimalarial drug chloroquine is the only agent of any consequence found to have any inhibiting effect on the uncoating of a virus, namely, Newcastle disease virus. 

Early workers [29] found that, like benzylpenicillin, vancomycin, ristocetin and bacitracin, novobiocin caused an excessive accumulation of cell wall precursor, uridine diphosphate-7V-acetylmuramic acid-L-alanine-D-glutamic acid-L-lysine-D-alanine-D-alanine (UDP-MurNAc-L-ala-D-glu-L-lys-D-ala-D-ala) in Staph, aureus and it was thus considered that novobiocin was a specific inhibitor of peptidoglycan synthesis with an effect similar to that of penicillin. However, subsequent studies led to the withdrawal of this hypothesis [26], since novobiocin caused the accumulation of other precursor-type compounds and also strongly inhibited both nucleic acid and protein synthesis in this organism. Thus, accumulation of particular precursors does not necessarily reflect the site of action of an antibacterial agent [30]. 

Protein synthesis and metabolism - Inhibitors of protein synthesis are effective antitumor, antiviral, and antimicrobial agents. Their specific site of action determines whether the desirable chemotherapeutic activities will predcminate over the untoward effects of these drugs. The effectiveness of chloramphenicol lies in its inhibitory effect on one of the few enzymatic reactions in protein synthesis that is specific to bacteria and its concomitant failure to affect protein synthesis in animal cells. 

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