A novel bifunctional N-acetylglutamate synthase-kinase from Xanthomonas campestris that is closely related to mammalian N-acetylglutamate synthase

Table 5 Effects of buffer components on enzymatic activities of XcNAGS-K. Synthase activity was assayed in 100 mM Tris-HCl, pH 9.0 that contains 100 mM NaCl and compounds listed in the table. Kinase activity was assayed in 100 mM MES buffer, pH 6.0 that contained 100 mM NaCl and compounds listed in the table. Enzymatic activity is defined as the number of μmoles of product formed in one minute.

Added Compound	Synthase Specific Activity (units/mg)	Added Compound	Kinase Specific Activity (units/mg)
100 mM NaCl	41.35 ± 1.05^a	100 mM NaCl	4.34 ± 0.15
100 mM MOPS	41.29 ± 1.55	100 mM MOPS	4.70 ± 0.11
100 mM Acetate	26.99 ± 0.64	100 mM Acetate	4.91 ± 0.05
100 mM MES	38.83 ± 0.54	100 Tris-HCl	4.07 ± 0.09
200 mM NaCl	29.91 ± 0.23	200 mM NaCl	4.75 ± 0.01

^anumbers represent averages of three measurements and associated standard errors

ISSN: 1471-2091