细菌视紫红质能化态时表面电位的非线性光学机制

Study on Nonlinear Optical Mechanism of Surface Potential in Energized Bacteriorhodopsin

用荧光标记物 1,8 ANS与细菌视紫红质结合 ,测得紫膜细菌视紫红质在能化态时的表面电位远大于非能化态时的对应值。在细菌视紫红质分子的激光四波混频实验中 ,应用激子表象理论 ,获得了紫膜能化态时的激子饱和密度和激子长度 ,说明在bR ANS络合物中 ,细菌视紫红质中色氨酸残基对ANS的激发能量转移效率提高 ,能化态时表面电荷密度增加 ,从而使非辐射共振转移变为激子转移 ,也证明了紫膜能化态时表面电位的非线性光学机制。

The effects of surface potential on the binding and fluorescence of 1 anilinonaphthalene 8 sulfonate (ANS) in suspensions of bacteriorhodopsin are investigated. The ANS binding depends on the surface potential which modulates the apparent binding constant of ANS on the bR membrane. The surface potential of the binding ANS measured in energized is larger than in nonenergized bR membrane. In the laser four wave mixing experiment, the saturation density and the length of exitons are obtained under the one\|dimensional exciton phase space filling model. The values result in improving the highly efficient energy transfer from the aromatic amino acids of bR to the bound ANS and in raising the density of the surface charge of the energized bR so that the non radiation resonant transfer is made to be exciton transfer, and the surface potential of energized bR has its nonlinear optical mechanism.