首页|金属离子对二甲亚砜依赖的RNA切割型脱氧核酶催化活性的影响

金属离子对二甲亚砜依赖的RNA切割型脱氧核酶催化活性的影响

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在高浓度有机溶剂中工作的RNA切割型脱氧核酶(RNA-cleaving DNAzyme,RCD)及其构筑的分子器件不仅拓展了DNA作为酶的能力,还可将功能核酸推进新的应用领域.本文研究了一个需要二甲亚砜才能工作的RCD(命名为E3)对金属离子的需求,发现二价金属离子对其催化活性至关重要,活性顺序为Zn2+,Mg2+>Fe2+>Pb2+>Mn2+>Co2+.以Mg2+或Zn2+为辅因子,表征了E3的速率-pH值关系及其与二者的结合比例.E3的催化速率-pH曲线在Mg2+存在下为"钟形",高速率的pH值范围为7.0～9.0;Zn2+存在下为"尖峰",速率最高时pH=7.0;E3与Mg2+和Zn2+的数量结合比例均为1∶1.另外,E3以Fe2+为辅因子时易失活,Fe2+被氧化成Fe3+是失活的关键,加入还原剂可使其复活.进一步研究发现,Cu2+,Fe3+和Ni2+等金属离子可抑制Mg2+或Zn2+的作用,使E3的催化活性急剧降低.本文研究结果为理解E3的性质及催化机制提供了有用信息.
Effect of Metal Ions on the Catalytical Activity of a DMSO-dependent RNA-cleaving DNAzyme
Engineering RNA-cleaving DNAzymes(RCDs)and RCD-based molecular devices that are highly functional in high content of organic co-solvents may not only expand the ability of DNAs as enzymes,but also promote functional nucleic acids for novel applications.In this work,we have investigated the requirement of divalent metal ions for a dimethyl sulfoxide(DMSO)-dependent RCD(named E3)that we previously reported.The divalent metal ions were proved to be crucial for E3 to function in 35%(volume fraction)DMSO,and the metal ions with the ability to activate E3 followed the order:Zn2+,Mg2+>Fe2+>Pb2+>Mn2+>Co2+.The rate-pH profile of E3 in Mg2+ showed a"bell"shaped curve with a plateau at the pH range from 7.0 to 9.0,yet a sharp peak at pH value of 7.0 in Zn2+.Moreover,both Zn2+ and Mg2+ bound to E3 at a number ratio of 1∶1.We also observed that E3 could be activated by Fe2+ in 35%DMSO,but quickly inactive by the rapid oxidation of Fe2+ to Fe3+.This inactivation of E3 could be further rescued by the addition of ascorbic acid.In addition,the catalytic activity of E3 in the presence of Zn2+ or Mg2+ was sharply inhibited with the competition of Cu2+,Ni2+,and Fe3+.These results are helpful for understanding the characterization and catalytical mechanism of the DMSO-dependent RCD.

RNA-cleaving DNAzymeFunctional nucleic acidOrganic solventMetal ion

崔力、李素慧、郑星、常天俊、邴涛

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河南理工大学资源环境学院,焦作 454003

中国科学院杭州医学研究所,杭州 310022

RNA切割型脱氧核酶 功能核酸 有机溶剂 金属离子

国家自然科学基金国家自然科学基金浙江省自然科学基金浙江省"尖兵领雁"研发攻关计划国家卫生健康委科学研究基金浙江省卫生健康重大科技计划浙江省核酸适体与临床诊治重点实验室开放基金

U170424122274139YXD24B04012023SDYXS0002WKJ-ZJ-24242022ASC001

2024

10.7503/cjcu20240004

高等学校化学学报
中华人民共和国教育部委托 吉林大学和南开大学

高等学校化学学报

CSTPCD北大核心
影响因子：1.067
ISSN：0251-0790
年,卷(期)：2024.45(4)
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