Question

what are Protein Synthesis Inhibitors -

what are DNA Synthesis Inhibitors -

what are Anti-Mycobacterium Antibiotics -

Answer 1

Protein synthesis inhibitors:

• Protein synthesis inhibitors are substances that prevent protein synthesis by inactivating components required for proteinsynthasis or preveinting elongation or formation of polypeptide chains.
• Antibiotics like Tetracycline, Chloramphenicol, act as protein synthesis inhibitors.
• The antibiotics which inhibit protein synthesis, should essentially inhibit the pathogen (bacteria) protein synthesis.
• The inhibitor may prevent initiation of protein synthesis by preventing formation of initiation complex in bacteria. Like Neomycin.
• Antibiotics acting as protein synthesis inhibitors specifically select 70s ribosomal subunit of bacteria and do not inhibit the eukaryotic 80 s ribosomal subunit. Thus, peptidyl transferase activity is prevented. Like Chloramphenicol.
• Some may block the A site, preventing the entry of Amino-acyl tRNA. Like Tetracycline.
• Other methods include, preventing formation of ribosomal assembly, inhibiting ribosomal translocation, translation termination inhibition.

DNA synthesis inhibitors:

• DNA synthesis inhibitors are compounds that prevent DNA replication or components that are involved in the nucleic acid generation.
• DNA synthesis inhibitors may inhibit action of DNA gyrase, like fluoroquinolones.
• Chain elongation may be prevented by inhibitors like Cisplatin, MMS.
• Inhibiting CDKs or checkpoints may affect ori site, like by Flavopyridol.
• Chain elongation during replication may be prevented by Acyclovir.

Antimycobacterium antibiotics:

• Mycobacterium cell has a waxy coat, containing mycolic acid, which make it impervious to Gram staining. Their cell wall contains high proportion of high-molecular-weight lipids. They may unpredictably acquire Gram positive or negative characteristics.
• Tuberculosis or TB is a contagious infection affecting majorly lungs, may spread to brain, spinal cord.
• The causal microorganism is a bacterium, called Mycobacterium tuberculosis (orMycobacterium bovis, Mycobacterium africanum, of the same family).
• Thus, the antimycobacterial drugs needs to penetrate the hydrophobic mycolic acid layer.

• Two common antomycobacterium drugs are resorcinomycin and pheganomycin.

• These drugs have hydrophobic lipid layers that help in their penetration through mycobacterium wall.

• Also Urydyl-peptide antibiotics like Rifampicin and Isoniazid can form pore in these bacterial membranes.