Shimayama T, Nishikawa S, Taira K
National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, MITI, Tsukuba Science City, Japan.
FEBS Lett. 1995 Jul 17;368(2):304-6. doi: 10.1016/0014-5793(95)00682-y.
As part of an ongoing effort to characterize structure-function relationships, activities of all-RNA and DNA-armed hammerhead ribozymes were examined. An analysis of the dependence on the concentration of Mg2+ ions of cleavage rates revealed that, whereas the kcat of the reaction catalyzed by the all-RNA ribozyme reached a maximum value of about 18 min-1 at a concentration of about 200 mM Mg2+ ions, that of the DNA-armed ribozyme increased linearly as the concentration of Mg2+ ions was increased above 300 mM, finally reaching a value of more than 100 min-1 at 700 mM Mg2+ ions. These results suggest that the potential activity of a hammerhead ribozyme might be greater than is usually recognized.
作为正在进行的表征结构-功能关系工作的一部分，对全RNA和DNA武装的锤头状核酶的活性进行了研究。对切割速率对Mg2+离子浓度的依赖性分析表明，全RNA核酶催化的反应的kcat在约200 mM Mg2+离子浓度下达到最大值约18 min-1，而DNA武装核酶的kcat在Mg2+离子浓度高于300 mM时随浓度线性增加，最终在700 mM Mg2+离子时达到超过100 min-1的值。这些结果表明，锤头状核酶的潜在活性可能比通常认为的要高。
