Characterization (B) of Arginine deiminase enzyme isolated from a local higher productive isolation of Enterococcus faecium M1

Abstract

Arginine deiminase (ADI) is a very active and stable enzyme especially when it used as a cancer treatment agent. In this study purified ADI from Enterococcus faecium M1was characterized, the maximum activity of ADI was 9.2 U/ml at 45ºC and still active for a wide range of temperatures. The activation energy of this enzyme was 6501.3 calorie/mol, ADI enzyme was very stable and had a maximum remaining activity at 20-37ºC.  Km and V max were 0.36 mM and 0.01298 M/min, respectively. When ADI incubated with EDTA and cysteine a slight inhibitory effect occurred on enzyme remaining activity (R.A) but it increased with 2-mercaptoethanol, which means that this enzyme may considered a thiol enzyme. The (R.A) of ADI increased in the presence of some metal ions like MnCl2, MgCl2, FeCl2, and HgCl2, but it little decreased with CuCl2, ZnSO4. The incubating results of ADI with some drugs and antibiotics were enhanced ADI activity, The enzyme remained active (90%) when it was stored in a freeze degree (-18Cº) for more than one year. By concluding, the present study was designed to characterize the important ADI enzyme in order to use it in many industrial applications in the future.