Etheno-substituted nucleotides and coenzymes: fluorescence and biological activity.

AbstractDefinition of the individual adenine binding sites of enzymes is important for many reasons. Rendering an adenine moiety fluorescent while retaining the biological activity of the molecule of which it is a component can provide useful binding information because of the fluorescence properties. The 1,N6-ethenoadenosine phosphates and, similarly, e-modified polynucleotides, RNA, and DNA have been synthesized, and their spectroscopic properties and interactions have been studied in depth. The use of e-substituted nucleotides has helped to clarify numerous enzyme reactions, including those of ATPase and energy transfer, ATP transphosphorylase, glyceraldehyde-3-phosphate dehydrogenase, phosphofructokinase, phosphorylase b, protein kinase, pyruvate kinase, ribonucleases, RNA ligase, and others. The binding of e-substituted nucleotides or polynucleotides to proteins has been determined for F- and G-actin, heavy meromyosin, tobacco mosaic virus protein, gene 32 protein of bacteriophage T4, and chloroplast...