TABLE 1.

Purification of Arthrobacter isonitrile hydratase

Step	Total protein	Total activity	Specific activity	Yield
	mg	units	units/mg	%
Cell-free extract	756	48.4 ± 0.1	0.0640 ± 0.0014	100
(NH4)2SO4 (0.20–0.35)	163	38.3 ± 0.6	0.235 ± 0.016	79.1
First Butyl-Toyopearl 650 M	35.2	29.1 ± 1.2	0.827 ± 0.039	60.1
Second Butyl-Toyopearl 650 M	21.4	20.0 ± 0.3	0.935 ± 0.012	41.3