Design, synthesis and characterisation of a peptide with oxaloacetate decarboxylase activity

The synthesis of Oxaldie-3, a synthetic 31-residue peptide with oxaloacetate decarboxylase activity, is described. Biophysical characterisation by gel filtration, CD and NMR spectroscopy indicated that the peptide adopted a folded structure in solution. Oxaldie-3 was an efficient catalyst at concentrations as low as 2 μM, 100-fold lower than the previously described Oxaldie-2, which relied on aggregating α-helices for activity. Oxaldie-3 speeded decarboxylation by more than three orders of magnitude relative to simple amines.