Microwave Irradiation to Hydrolyze Modified Peptide Bonds

Carboxyl terminal peptide bond was modified by thiohydantoin ring formation by the treatment of the C-terminal amino acid with trifluoroacetic anhydride and thiocyanate . The resulting modified peptide bond, peptidyl thiohydantoin, was then hydrolyzed by irradiating microwave (2450 MHz) in the presence of weak acid (2N HCI) for short duration (3 min). The thiohydantoin derivative of amino acid thus split was separated and identified by high performance liquid chromatography (HPLC). Microwave irradiation was found to be highly specific for the hydrolysis of the modified peptide bond and mild enough not to harm the residual peptide bonds.