title: Fluorescence decay studies of poly(riboadenylic acid) containing 1-N6-ethenoadenosine.
abstract: The fluorescence properties of the 1-N6-etheno derivatives of poly(riboadenylic acid) (poly(rA, epsilon rA)) have been examined. The fluorescence quantum yield of poly(rA, epsilon rA) decreases with an increase in the degree of the epsilon A substitution and is much smaller than that for epsilon AMP even for low degrees of epsilon A substitution. The nearest-neighbor interactions such as epsilon-adenine-adenine and epsilon-adenine-epsilon-adenine may be responsible for this behavior. It is found that the fluorescence decay kinetics obeys a three-exponential decay law for poly(rA, epsilon rA), suggesting that there exist at least three different stacked conformational states.
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives*; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000031:analogs & derivatives*; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: C004981:1,N(6)-ethenoadenine; D011061:Poly A; D000225:Adenine