H-Gly-His psi (NHCO)Lys-OH, partially modified retro-inverso analogue of the growth factor glycyl-L-histidyl-L-lysine with enhanced enzymatic stability.

A partially retro-inverso analogue of the natural growth factor GHK was synthesized, in which the -CONH- bond between histidine and lysine was modified as -NHCO-. This modification is not expected to perturb the spatial distribution of the side-chains, and therefore the binding processes, compared to the native peptide. In the synthesis of the analogue two possible systems for deblocking of N pi-Bom group of histidine have been applied and compared. An alternative method is also described for the incorporation of malonyllysine into the peptide chain. When evaluated with respect to resistance toward degradation by human plasma in vitro, the new peptide analogue showed approximately a ten-fold increase in stability versus the parent peptide.