AMINOGLYCOSIDE/RNA INTERACTIONS AND CORNEAL INFECTIONS

RNA分子能够形成精确的三维结构，这些结构可以作为有机小分子的结合位点。 了解RNA/小分子识别过程的规则，将有助于我们实现长期目标，即针对特定RNA结构重新设计拮抗剂，就像针对蛋白质酶和受体设计抑制剂一样。 设计用于抑制RNA分子的特异性抑制剂在眼科学和一般医学中，例如在设计可特异性干扰可导致视网膜变性的突变蛋白质的表达的小分子中，以及在设计可拮抗来自产生传染病的生物体的RNA分子的小分子中，可能引起极大的兴趣。该提案描述了获得对某些类别的天然存在的RNA拮抗剂（氨基糖苷类）被特定RNA分子识别的规则的理解的方法。 通过柱方法选择随机RNA分子，以高亲和力和特异性结合限定的含有氨基糖苷类的抗生素。 开发了新的定量荧光方法来确定抗生素与所选RNA适体结合的亲和力和化学计量。 开发了新的化学方法来揭示定义特定抗生素结合位点的适体区域。 计划对高亲和力结合适体进行高场NMR结构研究。 将确定识别特定氨基糖苷类的特异性RNA适体中的那些基序，并将其用作针对天然存在的RNA分子的特异性拮抗剂的未来设计的指导。在这种情况下，特别感兴趣的两种生物学上存在的RNA分子是原核16 S rRNA解码区和HIV-RRE转录激活因子区。 对氨基糖苷类化合物结合到解码区和RRE区的定量结构-活性研究导致了含有1，3（2）-羟胺部分的新型氨基糖苷类化合物多样性文库的设计。 针对RNA的解码和RRE区域的特异性拮抗剂将被制备和定量研究。这些拮抗剂有望成为设计用于治疗角膜感染的药物的起点。 总之，本文所述的研究将作为设计特异性RNA拮抗剂的一般程序的基础。

RNA molecules are able to form precise three-dimensional structures which can be binding-sites for small organic molecules. An understanding of the rules that govern RNA/small molecule recognition processes rules would allow for an approach to our long-term goal of the de novo design of antagonists directed at particular RNA structures, in much the same way that inhibitors are designed for protein-based enzymes and receptors. Specific inhibitors designed to inhibit RNA molecules could be of enormous interest in ophthalmology and generally in medicine, in the design, for example, of small-molecules that can specifically interfere with the expression of mutant proteins that can lead to retinal degeneration, and in the design of small molecules that can antagonize RNA molecules from infectious disease producing organisms. This proposal describes approaches to gaining an understanding of the rules by which certain classes of naturally occurring RNA antagonists, the aminoglycosides, are recognized by specific RNA molecules. Random RNA molecules are selected by column methods to bind to defined aminoglycoside containing antibiotics with high affinity and specificity. New quantitative fluorescence methods are developed to determine the affinities and stoichiometries of antibiotic binding to the selected RNA aptamers. Novel chemical approaches are developed to reveal the regions of the aptamers which define the binding-sites for the specific antibiotic. High field NMR structural studies on the high affinity binding aptamers are planned. Those motifs in the specific RNA aptamers which recognize particular aminoglycosides will be determined and used as a guide for the future design of specific antagonists directed against naturally occurring RNA molecules. Two biologically occurring RNA molecules of particular interest in this context are the procaryotic 16S rRNA decoding region and the HIV-RRE transcriptional activator region. Quantitative structure-activity studies on aminoglycoside binding to the decoding and RRE regions leads to the design of novel aminoglycosidemimetic diversity libraries containing l,3(2)-hydroxylamine moieties. Specific antagonists directed against the decoding and RRE regions of RNA will be prepared and studies quantitatively. These antagonists are expected to be starting points for the design of drugs useful in the treatment of corneal infections. Overall, the studies described herein will serve as the basis for a general program on the design of specific RNA antagonists.