SL MD4
Enzyme inhibitors as medicines
A bit like the antagonists!
• Noradrenaline (neurotransmitter)
• Fits into receptor site
• Electrical impulse sent to heart muscles
• Increases heart beat• Bad for heart
• Antagonist (propanolol) blocks receptor site
• Angiotensin I (substrate)
• Fits into active site of enzyme (ACE)
• Changes it to angiotensin II
• Increases blood pressure• Causes heart attacks and
strokes• ACE inhibitor (captopril)
blocks active site
What causes the high blood pressure?
angiotensin I angiotensin II + dipeptide
ACE - Angiotensin Converting Enzyme
Inactive Active – causes high blood pressure
Need enzyme inhibitor
Following the lead
Venom of Brazilian
Arrowhead Viper can
kill by lowering
blood pressure
It contained
several proteins
which were ACE
inhibitors
But proteins
are digested
in the stomach
Try Ass 9.
Back to the lead compounds ..
Active proteins from snake venom had the amino acid proline at the COOH end of the
chain.
After synthesising hundreds of compounds with proline in …
Not a protein so can be taken
orally!
Try Ass 10.
A bit like the antagonists!
• Noradrenaline (neurotransmitter)
• Fits into receptor site
• Electrical impulse sent to heart muscles
• Increases heart beat• Bad for heart
• Antagonist (propanolol) blocks receptor site
• Angiotensin I (substrate)
• Fits into active site of enzyme (ACE)
• Changes it to angiotensin II
• Increases blood pressure• Causes heart attacks and
strokes• ACE inhibitor (captopril)
blocks active site