Station 4 – Medicinal inhibitors

1. Station 4 – Medicinal inhibitors Example 1: HIV Protease inhibitors Inhibitor name: Protease inhibitors (many variations all under research) Function: Competitively inhibits HIV virus protease enzymes. Normally the virus uses this to cut viral RNA into smaller pieces so as into implant genes into the host cells DNA and hence replicate). How: The inhibitor binds specifically with the HIV protease enzymes active site preventing longer viral RNA pieces from bindings, as a result the RNA is not cut into smaller pieces so it cannot be implanted into the host cells DNA = no replication. Effect: A host cell can be infected by HIV but it cannot be ‘hijacked’ into making more HIV copies as a result of DNA implantation by the virus Normal (no inhibitor) With protease inhibitor (red)

2. Station 4 – Medicinal inhibitors Example 1: Suspected antifreeze poisoning treatment Inhibitor name: Ethanol (alcohol!) Function: Ethylene glycol is found in antifreeze, if ingested can be broken down by alcohol dehydrogenase (liver) forming extremely toxic oxalic acid = death. Ethanol if taken as a treatment can prevent this. How: Ethanol competitively inhibits alcohol dehydrogenase so give the patient a massive dose of ethanol so as to prevent ethylene glycol from interacting with alcohol dehydrogenase. Effect: Less oxalic acid is produced allowing the harmless ethylene glycol to be excreted. Better to be drunk than dead!! Broken down by alcohol dehydrogenase into Oxalic acid • Ethylene glycol Massive ethanol dosage Ethanol (inhibitor) Ethylene glycol excreted