University of Washington, Seattle, Department of Laboratory Medicine, USA.
Anal Chem. 2010 Mar 15;82(6):2498-504. doi: 10.1021/ac902887j.
The enzyme horseradish peroxidase is routinely used in immunohistochemistry to facilitate the chromogenic oxidation of 3,3'-diaminobenzidine, producing an insoluble brown precipitate marking the location and quantity of a tissue protein. In an effort to develop non-protein reagents for tissue diagnostics, we have developed a peroxidase DNAzyme construct that can be used as a chromogenic functional group in immunohistochemistry assays. The DNAzyme is based on a reported 18-mer G-quadruplex-forming DNA sequence, PS2.M, and has been covalently linked to its catalytically active moiety, hemin, to avoid the high background signal associated with the use of free hemin in histochemical studies. The activity of the covalent construct is maintained under conditions where G-quadruplex formation is unfavored and where the noncovalent DNAzyme-hemin complex has no activity.
辣根过氧化物酶通常用于免疫组织化学中，以促进 3,3'-二氨基联苯胺的显色氧化，产生不溶性的棕色沉淀物，标记组织蛋白的位置和数量。为了开发用于组织诊断的非蛋白试剂，我们开发了一种过氧化物酶 DNA 酶构建体，可作为免疫组织化学测定中的显色功能基团。该 DNA 酶基于报道的 18 个碱基 G-四链体形成 DNA 序列 PS2.M，并已与催化活性部分血红素共价连接，以避免在组织化学研究中使用游离血红素时出现的高背景信号。在不有利于 G-四链体形成的条件下，以及非共价 DNA 酶-血红素复合物没有活性的条件下，共价构建体的活性得以维持。
