Chemistry
How Covalent Inhibitors Target Active Site Residues in Enzyme Inactivation
Quick fact
Some drugs like aspirin and penicillin are covalent inhibitors: they form a permanent chemical bond with a specific amino acid in the enzyme's active site, irreversibly disabling the enzyme. This is why they have long-lasting effects even after the drug is cleared from the bloodstream.
Why this is interesting
Imagine a drug that doesn't just block an enzyme for a few minutes, but permanently 'locks' it shut. How could a single chemical bond lead to such a lasting effect?