摘要
利用亲和层析方法纯化了小麦草酸氧化酶 G和ψG,并对其生化特性进行了初步分析。G和 ψG的最适 pH 为 3.5,在 60℃以下较稳定。当草酸浓度大于0.2 mmol/L 时,G 和 ψG 的活性受到抑制。G 和 ψG 的Km值分别为0.084 和0.053 mmol/L。0.1 mmol/L的 EDTA、NH4 、Cl-、Mn2+、Mg2+、Na+ 和 K+ 对 G 和 ψG的活 2-NO3 和SO4 抑制G和ψG的活性。0.1 mmol/L的 H2PO4 - 2- -和HPO4 仅抑制G的活性。0.1mmol/L的核黄素、FMN 2-和FAD抑制ψG活性,G的活性则不受FAD和FMN的影响。
By affinity chromatography, germins G and ψG were purified from roots of wheat seedling and wheat embryos imbibition for 4 h (Table1). Characterization of the germins G and ψGwere studied.Theresults showed that Gand ψG were stable at temperatures lower than 60℃ (Fig.4), and had an optimum pH at 3.5 (Fig.1). The Km value of G for oxalate was 0.084 mmol/ L, while that of ψG was 0.053 mmol/L (Fig.3). Oxalate showed substrate inhibition effect above 0.2 mmol/Lon G and ψG (Fig.2). EDTA, NH4 , + Mn2+, Mg2+, Na+ and K+ at a concentration of 0.1 mmol/L had no effect on OxO activity. CO3 , NO3 and SO4 2- - 2- at a concentration of 0.1 mmol/L inhibited partially the activities of G and ψG, 0.1mmol/L Cu2+, Fe2+, Al3+ completely in- hibited the activities of G and ψG, but addition of 0.1 mmol/L EDTA partially relieved the inhibition, which indicated that metal cations may make the oxalate unavailable by chelating it. H2PO4 and HPO4 inhibited the activity of -2-G, but had no effect on ψG. Riboflavin, FMN and FAD inhibited ψG, but FMN and FAD had no effect on G (Table 2).
出处
《植物生理与分子生物学学报》
CAS
CSCD
2004年第4期393-398,共6页
Journal Of Plant Physiology and Molecular Biology
基金
广东省自然科学基金项目(No. 000594)资助。~~
关键词
小麦
萌发素
草酸氧化酶
纯化
特性
wheat
germin
oxalate oxidase
purification
characterization
