Purification and characterization of an arginine deiminase from Enterococcus faecalis SK32.001 producing citrulline

The crude enzyme of the arginine deiminase (ADI) from Enterococcus faecalis SK32.001 had been purified and the basic properties of ADI were investigated. The result of SDS-PAGE showed that ADI was purified to homogeneity level by fraction precipitated with ammonium sulfate, Hi Prep Q FF 16/10 and Sephadex G-75 gel filtration chromatography. The molecular mass of the purified ADI was estimated to be about 42 ku. The optimum temperature and p H of the purified ADI were 50℃ and 6.5, respectively. ADI activity kept stability under the temperature of 30⁴0℃ and at p H range of 5.5⁷.5. Among the metal irons, different concentrations of Zn2+could obviously affect the activity. 1mmo I/L Zn2+, 10 mmo I/L Co2+, 10 mmo I/L Ca2+and 10 mmo I/L Mg2+were the effective promoter while 10 mmo I/L Cu2+had poor improvement in the activity. The Michaelis constant was 1.33 mmo I/L and the maximum velocity was 2.41μmol/min.