Second generation specific-enzyme-activated rotaxane propeptides.

A [2]rotaxane, in which the peptidic axle is protected from degradation by the macrocyclic sheath and terminated with a novel glycosidase-cleavable stopper, is rendered water-soluble by derivatisation with tetra(ethylene glycol) (TetEG) or glucosylated tetra(ethylene glycol) (Glc-TetEG) chains using the CuAAC 'click' reaction. The Glc-TetEG-derivatised rotaxane propeptide is >50 000 times more soluble in aqueous media than the parent rotaxane. Activation of the water-soluble rotaxane propeptide with a β-galactosidase efficiently releases the parent peptide. This journal is © The Royal Society of Chemistry 2012