丝组二肽所含基团在其切割DNA反应中的作用

近 2 0年来 ,人工核酸切割试剂的研究一直是化学、生物化学和分子生物学中最为活跃的前沿领域之一1,2 ] .人工核酸切割试剂可以在足迹技术和核酸高级结构的研究中用作高分辨率的化学探针 ,还可以用于合成定点切割试剂3] .后者又被称为人工工具酶 ,是一种非常重要的分子生物学工具 ,在疾病的基因治疗、反义 PCR技术等领域中都具有重要的应用 .人工核酸切割试剂的切割机理主要有自由基机理和磷酸酯水解机理两大类 .相对于自由基机理 ,水解机理具有许多优点 ,使得水解型切割试剂具有更为广泛的应用 .对于 DNA,目前文献报道的水解型人工切…

Seryl-histidine Dipeptide Side Chains Effects on Its DNA Cleavage Reaction

The effects of the amino, hydroxyl, imidazole and carboxyl groups of Ser His on DNA cleavage reaction were studied. It was found that the amino and hydroxyl groups were essential for the DNA cleavage activity of Ser His, and that anyone of them blocked would result into the loss of cleavage activity. The carboxyl group was not the necessary group. The presence of the imidazole group would enhance the cleavage activity. However, the histidyl serine dipeptide, as the formula isomer of Ser His with the inverse peptide sequence, could not cleave DNA at all. Based on the above experimental results, a presumed cleavage mechanism of Ser His on DNA was proposed. WT5HZ]