Eriksson M, Eriksson S, Nordén B, Jernström B, Gräslund A
Department of Physical Chemistry, Chalmers University of Technology, Göteborg, Sweden.
Biopolymers. 1990;29(8-9):1249-60. doi: 10.1002/bip.360290814.
Fluorescence of (+)-anti-benzo(a)pyrene diol epoxide [(+)-anti-BPDE] covalently bound to poly(dG-dC) has been studied with steady-state and time-resolved techniques. Extensive formation of excimers is found, even at small (0.008) BPDE/nucleotide ratios. This indicates favored covalent binding to bases close to already modified guanines. Both fluorescence excitation spectra and lifetime measurements reveal two populations of (+)-anti-BPDE adducts: one that can form excimers and one that cannot. Three excimer lifetimes (4.5, 29, and 83 ns) are observed. Differently shifted monomer and excimer excitation spectra are discussed in terms of pyrene-pyrene exciton interactions, consistent with a distance shorter than 7 A between the excimer-forming BPDE chromophores.
已使用稳态和时间分辨技术研究了与聚（dG-dC）共价结合的（+）-反式苯并（a）芘二醇环氧化物[（+）-反式-BPDE]的荧光。即使在低（0.008）BPDE/核苷酸比率下，也发现了大量激基缔合物的形成。这表明有利于与已修饰鸟嘌呤附近的碱基发生共价结合。荧光激发光谱和寿命测量都揭示了两种（+）-反式-BPDE加合物群体：一种可以形成激基缔合物，另一种则不能。观察到三种激基缔合物寿命（4.5、29和83纳秒）。根据芘-芘激子相互作用讨论了不同位移的单体和激基缔合物激发光谱，这与形成激基缔合物的BPDE发色团之间的距离短于7埃一致。
