IF a small molecule allosteric potentiator of TTR's endogenous chaperone activity — identified by pH-biased virtual screening of ≥100,000 compounds against the A-strand/EF-helix interface of PDB 3GRG at simulated pH 5.5 (matching pancreatic secretory granule conditions), with scaffold prioritization for compounds predicted to stabilize the open/accessible conformation of this interface without contacting the T4 thyroxine-binding pocket, and validated by SPR Kd <500 nM and functional ThT-disaggregation assay showing ≥40% reversal of pre-formed hIAPP fibrils in the presence of TTR — is administered i.p. (10 mg/kg, 3×/week) to 12-week-old hIAPP-transgenic × db/db F1 hybrid male mice (n≥15/group) beginning after confirmed islet amyloid deposition (established by baseline thioflavin S at Week 12), for 16 weeks,

THEN the following will be observed at Week 28:

• Pancreatic islet amyloid burden reduced by ≥50% relative to vehicle (thioflavin S–positive area per islet cross-section)
• Beta-cell mass preserved or partially restored (≥30% higher vs. vehicle by insulin immunomorphometry)
• Fasting blood glucose ≤12 mM (vs. ≥18 mM expected in untreated hIAPP-Tg × db/db)
• TTR tetramer stability unimpaired: urea denaturation midpoint shift <2°C vs. baseline
• Circulating TTR–IAPP complex levels elevated (novel PD biomarker, detected by co-IP / proximity ligation in serum)

BECAUSE the following causal chain operates:

1. TTR possesses a structurally defined chaperone binding surface at its A-strand and EF-helix that directly contacts IAPP fibrils at the fibril tip/elongation interface, as established by co-crystallography (PDB 3GRG) and functional studies demonstrating TTR's anti-IAPP amyloidogenic activity (PMC8001701). This interaction is mechanistically distinct from TTR's T4-binding function.

2. Classical TTR stabilizers (tafamidis, diflunisal, AG10) lock the T4 pocket in a conformation that rigidifies the AB-loop/EF-helix region, thereby reducing the conformational flexibility required for TTR's chaperone function at the A-strand/EF-helix surface — creating the stability-efficacy paradox in which amyloidosis-protective stabilization simultaneously ablates the endogenous anti-IAPP mechanism (PMC8001701). This paradox is the central unresolved contradiction in TTR pharmacology.

3. Targeting the A-strand/EF-helix interface directly with an allosteric potentiator — rather than the T4 pocket — would instead stabilize the TTR–IAPP binding-competent conformation, increasing the affinity and dwell-time of TTR on IAPP fibril ends without perturbing tetrameric stability. [SPECULATIVE: the open A-strand conformation required for IAPP contact may be conformationally accessible and druggable, analogous to allosteric pockets exploited in other beta-sheet PPI targets.]

4. **Critically for REPAIR (not prevention): TTR does not merely cap fibril ends passively; molecular chaperones acting at fibril elongation interfaces have been demonstrated in ...

SENS category: LysoSENS