Other Formats: . ... The mutation affects enzyme folding and stability. ... 8000 U per liter of the optimized refolding medium with the specific activity of 1100-1500 U/mg (compared to 25, 000 U per liter and 2000 U/mg for the recombinant wild-type enzyme). ... The effect of hydrogen peroxide pretreatment on radiation-induced inactivation of the wild-type and mutant enzyme indirectly indicates participation of Trp-117 in electron transfer pathways through the enzyme molecule. ...