Pundir Chandra Shekhar, Chauhan Nar Singh, Bhambi Manu
Biochemistry Research Laboratory, Department of Biochemistry and Genetics, MD University, Rohtak, 124001 Haryana, India.
Anal Biochem. 2008 Mar 15;374(2):272-7. doi: 10.1016/j.ab.2007.11.008. Epub 2007 Nov 13.
Polyvinyl chloride (PVC) sheets are a promising material for enzyme immobilization owing to the PVC's properties such as being chemically inert, corrosion free, weather resistant, tough, lightweight, and maintenance free and having a high strength-to-weight ratio. In this study, this attractive material surface was chemically modified and exploited for covalent immobilization of oxalate oxidase using glutaraldehyde as a coupling agent. The enzyme was immobilized on activated PVC surface with a conjugation yield of 360 microg/cm(2). The scanning electron micrographs showed the microstructures on the PVC sheet surface revealing the successful immobilization of oxalate oxidase. A colorimetric method was adopted in evaluating enzymatic activity of immobilized and native oxalate oxidase. The immobilized enzyme retained 65% of specific activity of free enzyme. Slight changes were observed in the optimal pH, incubation temperature, and time for maximum activity of immobilized oxalate oxidase. PVC support showed no interference when immobilized oxalate oxidase was used for estimation of oxalic acid concentration in urine samples and showed a correlation of 0.998 with the values estimated with a commercially available Sigma kit. The overall results strengthen our view that PVC sheet can be used as a solid support for immobilization of enzymes and in the field of clinical diagnostics, environmental monitoring and remediation.
聚氯乙烯（PVC）片材因其具有化学惰性、无腐蚀性、耐候性、坚韧、轻质、免维护以及高强度重量比等特性，是一种很有前景的酶固定化材料。在本研究中，利用戊二醛作为偶联剂，对这种有吸引力的材料表面进行化学修饰，并用于草酸盐氧化酶的共价固定化。酶以360微克/平方厘米的结合产率固定在活化的PVC表面。扫描电子显微镜照片显示了PVC片材表面的微观结构，表明草酸盐氧化酶成功固定化。采用比色法评估固定化和天然草酸盐氧化酶的酶活性。固定化酶保留了游离酶比活性的65%。观察到固定化草酸盐氧化酶的最佳pH值、孵育温度和最大活性时间有轻微变化。当使用固定化草酸盐氧化酶估计尿液样本中的草酸浓度时，PVC载体没有干扰，并且与使用市售Sigma试剂盒估计的值的相关性为0.998。总体结果强化了我们的观点，即PVC片材可作为酶固定化的固体支持物，并应用于临床诊断、环境监测和修复领域。
