Crystal structure shows how tinlarebant disrupts RBP4 and transthyretin partnership to cut circulating RBP4
- Tinlarebant, an A1120-derived RBP4 antagonist reported to slow lesion growth in Stargardt disease, had no disclosed mechanism until now.
- Fluorescence and crystallography show it binds very tightly and displaces retinol from the RBP4 pocket.
- Once bound, RBP4 no longer forms a complex with transthyretin, owing to conformational and steric changes seen in the structure.
- A single dose in mice markedly lowered plasma RBP4.
💡 Points Based on the abstract
The pharmacodynamic readout matters more than the structure here. Knocking down circulating RBP4 is a clean marker, yet it was shown after a single mouse dose. Repeat-dose exposure plotted against RBP4 suppression is the next step, along with evidence that retinol delivery to the retina falls in parallel. Whether an antagonist occupying the binding pocket also hits other lipocalins remains open.
Structural and biochemical basis for retinol‐binding protein 4 antagonism by tinlarebant ↗