First clear positive result in the project. Ran Phase 1 on Modal L4
(~$0.70). Boltz-2 P(binder), cofactors co-folded:
- HDAC2 (+Zn): vorinostat 0.9994 vs negatives ~0.1 -> PASS, decisive
- hemoglobin (+heme): voxelotor 0.46 -> PASS (weak; covalent/tetramer)
- PKR (+FBP/Mg): mitapivat 0.32 < hydroxyurea 0.40 -> FAIL (allosteric)
HDAC2/Zn is the exact case classical Vina failed (no metal term, 7.9A
redock). Co-folding handles the Zn-chelation chemistry -> the structure-
binding modality pivot (PLAN §12) is validated on its decisive test.
Engineering fixes that got it running: image needs cuequivariance kernels;
max_containers=1 so weights download once (parallel corrupted the shared-
Volume checkpoint); rank by P(binder) not affinity_pred_value (sign).
Adds docs/results/phase1_affinity.csv (committed; raw under data/ gitignored).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
