CAJ | 학술논문

在水稻谷糠中检测到草酸氧化酶(OxO,EC1.2.3.4)的活性,其主要存在于细胞壁中,最适pH值为2.5,Km值为0.63mmol/L,当底物草酸的浓度大于2.0mmol/L时会出现底物抑制;此外,该酶热稳定性很高,而且对胃蛋白酶、SDS和高浓度的NaCl不敏感;1mmol/L的EDTA、NH4~+、Cl~-、Mn~(2+)、CO_3~(2-)、Na~+、K~+、H2PO_4~-、SO_4~(2-)、Fe~(2+)和PO_4~(3-)对其活性没有影响,但1mmol/L的NO_3~-、CO~(2+)、Zn~(2+)、Cu~(2+)、Mg~(2+)、Ca~(2+)和Al~(3+)会抑制它的活性.因此,谷糠中的OxO可能被广泛用于测定草酸含量.
재수도곡강중검측도초산양화매(OxO,EC1.2.3.4)적활성,기주요존재우세포벽중,최괄pH치위2.5,Km치위0.63mmol/L,당저물초산적농도대우2.0mmol/L시회출현저물억제;차외,해매열은정성흔고,이차대위단백매、SDS화고농도적NaCl불민감;1mmol/L적EDTA、NH4~+、Cl~-、Mn~(2+)、CO_3~(2-)、Na~+、K~+、H2PO_4~-、SO_4~(2-)、Fe~(2+)화PO_4~(3-)대기활성몰유영향,단1mmol/L적NO_3~-、CO~(2+)、Zn~(2+)、Cu~(2+)、Mg~(2+)、Ca~(2+)화Al~(3+)회억제타적활성.인차,곡강중적OxO가능피엄범용우측정초산함량.
The activity of oxalate oxidase (OxO, EC1.2.3.4) was detected in rice bran and this enzyme was found to be mainly rich in cell wall. The optimal reaction pH and K_m values of this enzyme towards oxalate as a substrate were 2.5 and 0.63 mmol/L,respectively. An inhibitory effect against OxO was observed when oxalate concentration was over 2.0 mmol/L. Meanwhile, the enzyme exhibited high thermo-stability and resistance to SDS, pepsin and NaC1. Although EDTA, NH_4~+, Cl~-, Mn~(2+), CO_3~(2-), Na~+,K~+, H_2PO_4~-, SO_4~(2-), Fe~(2+) and PO_4~(3-) at the concentration of 1 mmol/L had no effect on OxO activity, NO_3~-, Co~(2+), Zn~(2+),Cu~(2+),Mg~(2+), Ca~(2+)and Al~(3+) at the identical concentration exhibited strong an inhibitory effect against OxO activity. Therefore, OxO from rice bran may be widely used to detect oxalate level, which will provide theoretical evidence for the ingredient analysis of functional foods.