Singh Geeta, Tanwar Durgesh N, Pundir C S
Biochemistry Research Laboratory, Dept. of BioSciences, M D University, Rohtak 124 001 (Haryana), India.
Indian J Biochem Biophys. 2002 Dec;39(6):397-400.
A Cl- and NO3- insensitive oxalate oxidase, purified from the roots of 10-day old seedlings of grain Sorghum has been immobilized on polyvinyl alcohol (PVA) membrane through entrapment with 96.07% retention of initial activity. The membrane bound enzyme showed an increase in optimum pH (from 5.0 to 6.5), time of incubation (from 5 to 10 min) and Km for oxalate (from 0.38 to 6.23 mM), but decrease in incubation temperature for maximum activity (from 37 to 30 degrees C) and Vmax (from 70 nmol/min/ml to 9.7 nmol H2O2/min) and was unaffected by Cl- and NO3. The membrane bound enzyme lost 50% of its initial activity after 30 days of storage at room temperature. The use of membrane bound oxalate oxidase in determination of serum oxalate of urinary stone patients is demonstrated.
从10日龄谷物高粱幼苗根部纯化得到的一种对氯离子和硝酸根离子不敏感的草酸氧化酶，通过包埋法固定在聚乙烯醇（PVA）膜上，初始活性保留率为96.07%。膜结合酶的最适pH值升高（从5.0升至6.5），孵育时间延长（从5分钟延长至10分钟），草酸的米氏常数增大（从0.38毫摩尔升至6.23毫摩尔），但最大活性的孵育温度降低（从37摄氏度降至30摄氏度），最大反应速度减小（从70纳摩尔/分钟/毫升降至9.7纳摩尔过氧化氢/分钟），且不受氯离子和硝酸根离子影响。室温下储存30天后，膜结合酶丧失了50%的初始活性。本文展示了膜结合草酸氧化酶在测定尿路结石患者血清草酸中的应用。
