D-retro-inverso peptide design

A mirror-image peptide that proteases cannot chew

Ordinary peptides struggle as drugs, because the body's proteases cut peptide bonds for a living. FOXO4-DRI uses a trick borrowed from peptide chemistry, the D-retro-inverso design, which reviews describe as a way to resist proteolysis: the molecule is assembled from mirror-image amino acids in reverse order, which keeps a side-chain arrangement similar to the original while the backbone is not an ordinary substrate.

This unit explains what DRI actually means, why a cell-penetrating tag was bolted on, and the honest trade-offs the design carries.