菌紫质D96N样品的光暗适应型及其转化机制

LIGHT-ADAPTED AND DARK-ADAPTED BR D96N ANDTHEIR TRANSFORMATION MECHANISM

通过对菌紫质D96N基因突变形成的薄膜样品在光照下动态光谱的测定和分析 ,研究了此样品的光适应型、暗适应型特性及其之间的转化机制。实验证实 ,样品受光照激发后很快从暗适应型 (D态 )经过光适应型 (B态 )进入光循环 ,经过一系列的光化学中间体到达较稳定的M态。M态经过约1小时热驰豫完全回到光适应型B态 ,B态再经过24小时缓慢热驰豫完全回到暗适应型D态。B态受光则进入光循环 ,不受光则转化为D态 ,从而认为B态是菌紫质光循环路径中一个重要的分支节点。据此 ,提出了该样品在光照下B 。

The properties of light-adapted and dark-adapted BR D96N films and their transformation mechanism were studied by measuring and analyzing the kinetic absorption spectra of the sample under light illumination. It is confirmed that under the illumination of light the dark-adapted (D state)BR is quickly turned into the light-adapted (B state), and undergoes a photochemical cycle then through a sequence of intermediates of J, K, L,comes into a more stable intermediate-M state. M state relaxes to B state in about one hour. B state converts completely into D state after 24 hours. B state initiates the photochemical cycle under illumination, while it can transform into D state in the dark. So B state is a key intermediate in the BR photochemical cycle. A model on the transformation of D, B and M states is given based on the experimental results.