Identification, Cloning, and Characterization of l-Phenylserine Dehydrogenase from Pseudomonas syringae NK-15

Table 1

Purification of recombinant L-phenylserine dehydrogenase.

Step	Activity	Protein	Specific activity	Yield
	units	mg	units/mg	%
Crude extract	1400	1100	1.3	100
(NH4)2SO4 fractionation	1800	880	2.0	130
Q-Sepharose FF	1100	180	6.1	79
Phenyl-Sepharose	140	22	6.5	10

The enzyme activity was measured with 20 mM DL-threo-𝛽-phenylserine and 2.5 mM NAD⁺ in 0.2 M glycine-KCl-KOH buffer (pH 10.5) at 30^∘C.