Hendrix C, Mahieu M, Anné J, Van Calenbergh S, Van Aerschot A, Content J, Herdewijn P
Laboratory for Medicinal Chemistry, Rega Institute, K. U. Leuven, Belgium.
Biochem Biophys Res Commun. 1995 May 5;210(1):67-73. doi: 10.1006/bbrc.1995.1628.
Hammerhead ribozymes may be of great therapeutic importance, since they can, in theory, be developed to cleave any undesired target RNA. In order to design ribozymes which are stable against endogenous RNases, we incorporated 2'-acetamido-2'-deoxynucleosides in the catalytic core of a hammerhead ribozyme. The 2'-acetamido function has, like the hydroxyl group, both proton donor and proton acceptor capacities, which seem to be crucial for efficient catalytic activity. However, the presence of 2'-acetamido-2'-deoxypyrimidine residues in the catalytic core caused a considerable drop in cleavage rate. Replacement of the purine residues led to complete loss of the catalytic activity. Surprisingly, these 2'-modifications showed no beneficial influence on the stability of the ribozymes against RNases present in cell culture supernatant containing 10% fetal calf serum.
锤头状核酶可能具有重大的治疗意义，因为理论上它们可以被开发用于切割任何不需要的靶RNA。为了设计对内源性核糖核酸酶稳定的核酶，我们在锤头状核酶的催化核心中引入了2'-乙酰氨基-2'-脱氧核苷。2'-乙酰氨基官能团与羟基一样，具有质子供体和质子受体能力，这似乎对高效催化活性至关重要。然而，催化核心中2'-乙酰氨基-2'-脱氧嘧啶残基的存在导致切割速率大幅下降。嘌呤残基的替换导致催化活性完全丧失。令人惊讶的是，这些2'-修饰对核酶在含有10%胎牛血清的细胞培养上清液中对核糖核酸酶的稳定性没有产生有益影响。
