The Use of Microwave Radiation in Combination with EDTA as an Outer Membrane Disruption Technique to Preserve Metalloenzyme Activity in Escherichia coli

Abstract

Ethylenediaminetetraacetic acid (EDTA) is commonly used in the isolation of bacterial 2+ proteins to disrupt the outer membrane of gram negative cells by chelating Mg ions, essential to outer membrane stability. The chelation properties of EDTA can interfere with metalloenzymatic activity, whose catalysis is dependant upon the cationic cofactors that are chelated by EDTA. An alternative method to disrupt the outer membrane while preserving metalloenzyme activity is athermal microwave radiation. This study demonstrated that athermal microwave radiation succeeds in decreasing membrane integrity in E.coli C29, and that maximal enzymatic activity of the metalloenzyme alkaline phosphatase was achieved using a membrane disruption technique that combined EDTA treatment and athermal microwave radiation.