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Signalling & repair
FOXO4-DRI
D-retro-inverso peptide derived from FOXO4, researched as a disruptor of the FOXO4-p53 interaction in senescent cells.
| Purity | >98% |
Research background
A senescent cell has stopped dividing but does not die, and that is precisely the problem this peptide addresses. In those cells FOXO4 accumulates and holds p53 in nuclear foci; with p53 sequestered, the apoptosis order never arrives and the cell remains indefinitely. FOXO4-DRI competes for that binding: by displacing FOXO4 it releases p53, and apoptosis is triggered only where that interaction was active. That is the selectivity that made it known following the work of Baar and colleagues published in Cell in 2017.
The D-retro-inverso topology is the other thing worth understanding. It is built with D-amino acids in reverse order, so that the side chains sit in space almost as in the natural peptide while the backbone is not recognised by proteases. It is a general stabilisation strategy, and this peptide is one of its textbook examples.
Its technical table is deliberately left empty. FOXO4-DRI has no registered CAS number and its mass depends on the exact construct: suppliers publish sequences that do not match one another, and molecular weights that do not either. Rather than copy a figure that cannot be checked, this page prefers to say it does not have one.
Reconstitution and handling
- Work on a clean surface and disinfect the vial stopper with an alcohol wipe before piercing it.
- Add the bacteriostatic water slowly, letting it run down the inner wall of the vial rather than landing on the powder.
- Do not shake. Swirl the vial gently until the lyophilized powder has fully dissolved: vigorous agitation degrades the peptide.
- The solution should come out clear. If it turns cloudy or shows suspended particles, do not use it.
Storage and stability
- Before reconstitution: refrigerated between 2 and 8 °C, protected from light and moisture.
- After reconstitution: in the fridge and away from light. In solution the peptide lasts far less than as a powder, so it is best used soon.
- Avoid freeze-thaw cycles.
