Sakamoto T, Kuwabara T, Tanaka Y, Kurihara Y, Katahira M, Uesugi S
Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan.
Nucleic Acids Symp Ser. 1995(34):131-2.
Properties of a mutant hepatitis delta virus (HDV) ribozyme which consists of three RNA oligomer strands (Fig. 1c) are described. Effects of the MgCl2 concentration, pH and temperature on the cleavage reaction were examined. The dependence on these conditions did not resemble those of the published data for other HDV ribozymes (the parent) which consist of single-strand RNA of about 90 nt. The highest cleavage for the mutant was observed at 35-40 degrees C, while the parent ribozymes show higher activity at around 60 degrees C than at 40 degrees C. Thus we suppose that the most of the parent ribozymes are in inactive conformation at 40 degrees C and high temperature is needed to change the equilibrium between the inactive and active conformations. Since the Tm of the mutant was around 50 degrees C, these results suggest that the most of the mutant ribozyme complex molecules are in active conformation at 40 degrees C.
描述了一种由三条RNA寡聚体链组成的突变型丁型肝炎病毒（HDV）核酶的特性（图1c）。研究了MgCl2浓度、pH值和温度对切割反应的影响。对这些条件的依赖性与已发表的其他HDV核酶（亲本）的数据不同，其他HDV核酶由约90个核苷酸的单链RNA组成。突变型核酶在35-40℃时切割活性最高，而亲本核酶在60℃左右比在40℃时表现出更高的活性。因此我们推测，大多数亲本核酶在40℃时处于无活性构象，需要高温来改变无活性和活性构象之间的平衡。由于突变型核酶的熔解温度约为50℃，这些结果表明，大多数突变型核酶复合分子在40℃时处于活性构象。
