[Simplified method of isolating glutamate decarboxylase from Escherichia coli]

A modified method for preparation of partially and highly purified glutamate decarboxylase from E. coli str. 600 was developed. Cell disruption was achieved by brief autolysis (6 hours at 37 degrees C). Residues of nucleic acids and acidic proteins were removed by means of streptomycin sulfate that replace protamine sulfate. The use of modified ion-exchange chromatography and improved monitoring of enzyme elution from DEAE-cellulose columns helped to prepare highly purified glutamate decarboxylase, the crystallization stage being omitted. Preparation of partially and highly purified enzyme with specific activities of 6,000-14,000 and 20,000-35,000 microliter CO2/10 min/mg protein, respectively were obtained.