Mora María E, Bari Sara E, Awruch Josefina, Delfino José M
Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina.
Bioorg Med Chem. 2003 Oct 15;11(21):4661-72. doi: 10.1016/s0968-0896(03)00479-6.
The cyclic 2,18-bridged biliverdin (2) is excreted in rat bile without reduction to the corresponding bilirubin. Conformational analysis, employing an optimized Monte Carlo method and a mixed Monte Carlo/stochastic dynamics, reveals that biliverdin IXalpha (1) and the cyclic analogue 2 adopt 'lock washer' conformations, stabilized by the presence of intramolecular hydrogen bonds between N23...H22N and, to a lesser extent, between N23...H24N. Although 2 is very similar in overall shape to 1, the former adopts a 'locked lock washer' conformation unable to undergo fluctuations, thus possibly hampering a proper recognition by biliverdin reductase.
环状2,18 - 桥连胆绿素（2）在大鼠胆汁中排泄时未还原为相应的胆红素。采用优化的蒙特卡罗方法和混合蒙特卡罗/随机动力学进行的构象分析表明，胆绿素IXα（1）和环状类似物2呈现“锁环垫圈”构象，通过N23...H22N之间以及程度稍小的N23...H24N之间的分子内氢键得以稳定。尽管2在整体形状上与1非常相似，但前者采用了一种无法波动的“锁定锁环垫圈”构象，因此可能妨碍胆绿素还原酶的正常识别。
