Enzyme Immobilized Magnetic Nanoparticles (EMNPs) were injected and magnetically retained, as a microreactor, in the capillary of a capillary electrophoresis (CE) setup with UV detection. The enzyme horseradish peroxidase (HRP) was chemically immobilized onto commercially available magnetic 300 nm diameter nanoparticles. Paracetamol (acetaminophen: N-acetyl-p-aminophenol), a common analgesic drug, was used as model drug compound. The enzymatic reaction was studied in-line by CE in 12.5 mM phosphate buffer pH 7.4 containing 20 mg/ml sulfated-β- cyclodextrin and 0.1 mM hydrogen peroxide. By means of the developed setup, the apparent Michaelis Menten constant between HRP and acetaminophen (APAP) was determined as Km app = 53±5 μM. This approach was found to be of interest for enzyme kinetics studies with short time resolution condition. Based on our results and from the literature data, it was possible to infer that the in-line generated product was an APAP dimer. Higher enzyme immobilized beads loading in the CE setup generated the APAP dimer with two additional minor peaks likely attributing to APAP trimer and tetramer. N-acetyl- p-benzoquinone imine (NAPQI) was not generated during APAP short time migration through the in-line microreactor.
将酶固定化磁性纳米粒子(
EMNPs)作为微反应器注入毛细管电泳(CE)装置的毛细管中,并通过磁
铁固定,同时进行紫外检测。将酶
辣根过氧化物酶(HRP)通过
化学方法固定在市面上可买到的直径为300 nm的磁性纳米粒子上。将常用止痛药
扑热息痛(
对乙酰氨基酚:N-乙酰-
对氨基苯酚)作为模型药物化合物。通过CE在线研究了在含有20 mg/ml
硫酸化-β-
环糊精和0.1 mM
过氧化氢的12.5 mM
磷酸盐缓冲液pH 7.4中的酶促反应。通过开发的装置,确定了HRP和
扑热息痛(APAP)之间的表观Michaelis Menten常数为Km app = 53±5 μM。这种方法被认为适用于短时间分辨率条件下的酶动力学研究。根据我们的结果和文献数据,可以推断出在线生成的产物是APAP二聚体。在CE装置中,更高的酶固定化微珠负载量产生了APAP二聚体,并产生了两个较小的峰,可能归因于APAP三聚体和四聚体。在APAP通过在线微反应器短时间迁移期间,没有产生N-乙酰-
对苯醌亚胺(NAPQI)。