DNA 适体-铂复合物的过氧化物酶活性制备顺铂。

Peroxidase activity of DNA aptamer-pt complexes prepared with cisplatin.

机构信息

Department of Chemical and Materials Engineering, National Central University, 300 Jhongda Road, Jhongli, Taoyuan 32001, Taiwan.

出版信息

J Biomater Sci Polym Ed. 2010;21(1):67-82. doi: 10.1163/156856209X410238.

DOI:10.1163/156856209X410238

PMID:20040154

Abstract

DNA aptamers carrying Pt nanoparticles prepared with cisplatin showed peroxidase enzymatic activity while retaining the specific binding ability of the aptamers. Optimal preparation conditions of DNA-Pt complex prepared with cisplatin were investigated on the synthesis at pH 7-11, a reaction time of 1-18 h and 90 degrees C. The enzymatic reaction of DNA-Pt complex obeyed Michaelis-Menten kinetics. K(M) for the DNA-Pt complex was found to be of the same order as K(M) for hemin and hemin-DNA complex, but one order of magnitude higher than that of horseradish peroxidase. A sandwich type of DNA enzyme-linked aptamer assay (DLAA) using DNA-Pt complex successively detected target protein of thrombin. DLAA using DNA-Pt complex fractioned by ultrafiltration membranes having a molecular weight cut-off of 30 000 and 300 000 showed 1.9-times higher sensitivity than DLAA using DNA-Pt complex without fraction. The DNA-Pt complex having specific size was effective for the sensitive detection of thrombin in DLAA.

摘要

携带铂纳米颗粒的 DNA 适体通过顺铂制备显示过氧化物酶酶活性，同时保留适体的特异性结合能力。研究了在 pH 7-11、1-18 h 和 90°C 下用顺铂合成时 DNA-Pt 配合物的最佳制备条件。DNA-Pt 配合物的酶反应遵循米氏动力学。发现 DNA-Pt 配合物的 K(M)与血红素和血红素-DNA 配合物的 K(M)处于同一数量级，但比辣根过氧化物酶高一个数量级。使用 DNA-Pt 配合物的三明治型 DNA 酶连接适体测定法（DLAA）成功地检测了凝血酶的靶蛋白。使用超滤膜（分子量截止值为 30000 和 300000）分离的 DNA-Pt 配合物的 DLAA 比未分离的 DNA-Pt 配合物的 DLAA 显示出 1.9 倍的更高灵敏度。具有特定尺寸的 DNA-Pt 配合物对于在 DLAA 中灵敏检测凝血酶是有效的。