Cationic heterooligopeptides by ficain-catalyzed co-oligomerization of lysine and methionine ethylesters.

Oligopeptides are of high importance for various industrial applications, e.g. cosmetical or medical. Homooligomerizations and co-oligomerizations with anionic amino acid esters are well described but a successful synthesis of cationic heterooligopeptides has been missing so far. The present study reports the ficain-catalyzed heterooligomerizations of LysOEt with MetOEt, leading to cationic heterooligopeptides with a yield up to 49.5% (w/w). MALDI-ToF/ToF-MS analyses proved successful syntheses of cationic heterooligopeptides with a DP between 7 and 10 amino acid residues, with the enzyme exhibiting a clear preference for methionine.