What a learner can do afterwards
- Designs a set of analogues that isolates the contribution of one substituent
- Reads a potency table and states which structural feature the target requires
- Distinguishes a real potency gain from an artefact of assay conditions or compound aggregation
- Explains what ligand efficiency measures and why potency alone is a poor guide
1 · Read
A screening hit is a starting point, not a drug. To learn what one substituent does, you make analogues that differ at that spot alone. Then any shift in potency belongs to that single change.
Lay the analogues out in a potency table and hunt for a pattern. A feature found in every strong compound and missing in the weak ones is one the target requires. If a weak compound carries the feature too, it helps but is not the whole story.
A better number is not always better binding. Assay conditions can flatter a compound, and some compounds clump together in solution and fake activity. Change the conditions and retest before you trust a gain.
Potency alone is a poor guide, because bigger molecules often score higher by bulk. Ligand efficiency measures potency per unit of size, so it rewards compact strength. Pick the efficient compound as your lead, then grow it with care.
Change one spot at a time, read the table for the pattern, distrust flattering numbers, and let efficiency guide the next compounds.
2 · Watch
Take it off screen
Where it sits
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.