Characterization of glutathione transferases involved in the pathogenicity of Alternaria brassicicola

BMC Microbiology

Table 2 Kinetic parameters of AbGSTs in enzymatic assays

	AbGTT1.2	AbGSTO1	AbUre2pB1	AbGSTFuA1
K _m (mM)
CDNB	1.82 ± 0.33	ND	5.01 ± 0.40	0.40 ± 0.02
Al-ITC	ND	ND	ND	0.12 ± 0.02
Bz-ITC	ND	ND	ND	0.18 ± 0.03
Ph-ITC	ND	ND	ND	0.11 ± 0.02
Cu-OOH	0.12 ± 0.04	ND	0.77 ± 0.06	ND
β-ME-SG	ND	1.12 ± 0.02	ND	ND
GSH	1.33 ± 0.10	0.45 ± 0.13	0.87 ± 0.02	0.50 ± 0.0004
k _cat (s ^-1 )
CDNB	0.10 ± 0.05	ND	1.50 ± 0.08	38.18 ± 6.10
Al-ITC	ND	ND	ND	76.80 ± 11.64
Bz-ITC	ND	ND	ND	11.81 ± 1.82
Ph-ITC	ND	ND	ND	20.54 ± 2.96
Cu-OOH	6.82 ± 1.18	ND	0.20 ± 0.01	ND
β-ME-SG	ND	49.00 ± 9.40	ND	ND

The apparent K _m values for all compounds were determined using a 0.1-50 mM concentration range in the presence of 3 mM GSH. The K _m value for GSH was determined with 2 mM CDNB and a 0.01 to 10 mM GSH concentration range. The apparent K _m and k _cat values were calculated by nonlinear regression using the Michaelis-Menten equation (r2 > 0.99). Data are represented as mean ± S.D. (n ± 3)
ND Not detectable

ISSN: 1471-2180