title: Fluorescence studies on the complex formation between poly(rA) containing 1,N6-ethenoadenosine and poly(rU).
abstract: The interaction of the 1,N6-etheno derivatives of poly(rA) (poly(epsilon rA] with poly(rU) has been studied by absorption and fluorescence spectroscopy. The stoichiometry of the interaction is found to be 1 epsilon A:1 rU and 1 epsilon A:2 rU as well as in the case of poly(rA)-poly(rU) interaction. The fluorescence properties, including the intensity and polarization of fluorescence, respond to the conformational transition of poly(epsilon rA)-poly(rU) complexes. The introduction of epsilon A groups into poly(rA) results in a marked decrease in the melting temperature, suggesting that epsilon A may destabilize the helical structure. The three-exponential decay law obtained with poly(epsilon rA)-poly(rU) complexes indicates the existence of at least three different stacked conformational states.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives*; D009690:Nucleic Acid Conformation; D011061:Poly A; D011072:Poly U; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013816:Thermodynamics
chemical_list: D011061:Poly A; D011072:Poly U; C007640:1,N(6)-ethenoadenosine; D000241:Adenosine