Design and synthesis of de novo peptide for manganese binding

Abstract

The de novo peptide with 63-residues (MHB) has been synthesized biochemically and used for the binding of manganese (II) ions. In designed peptide, the leucine of the peptide dA1 (prototype) was replaced by His27 and Asp41 for binding the manganese (II) ions. The different chromatography studies and mass determination showed that new peptide folds into a monomeric, highly helical with a active site structure similar to the native Mn-SOD in an aqueous solution. Electron paramagnetic resonance (EPR) study suggested that the peptide binds single manganese (II) ion per molecule loosely with K D value of about 36 μM. The circular dichroism (CD) studies demonstrated that the helical contents of the peptide did not change significantly even after binding the metal ions. The SOD activity study of the Mn-peptide complex showed that the IC50 values is 8.08 μM. © 2006 Springer Science+Business Media, Inc.