细菌视紫红质高分辨图象存储中吸收和散射现象的实验研究

本文利用细菌视紫红质变种材料BR_D96N的基态和M态实现了图象的高分辨存储.实验研究了该样品的吸收特性;在此基础上分析了散射光对BR膜图象质量的影响,并通过合理的控制激发光强和激发时间在BR膜样品上得到分辨率为800lp/mm的高分辨图象.     

Modification and photosensitization of size-quantized particulate CdS film photoelectrodes with bacteriorhodopsin (BR)

Bacteriorhodopsin (BR) was used to modify the surface of a novel size-quantized particulate CdS photoelectrode fabricated by electro-deposition. The photovoltaic features and interfacial electron transfer of the electrodes were studied by surface photovoltaic spectroscopy and a photoelectrochemical method. The results show that BR-modified CdS film photoelectrodes achieve a higher photocurrent yield due to the incorporation of the proton pump BR. On the basis of the observations, the mechanisms of photosensitization and interfacial electron transfer are proposed.     

细菌视紫红质的光电特性

利用电沉积法在ITO导电玻璃上沉积的BR紫膜薄膜,制作ITO/BRPMFILM/PARYLENEFILM/AL电池结构系统。在可见光的照射下,光电池系统对光强的变化产生微分响应电流信号,其上升时间不随光强变化量大小而变;并且光电流与光强的变化量呈线性关系。但是与文献1不同的一点是:在光强以相等的改变量增大或减小时产生的正、反微分响应电流(与质子泵方向相比)幅值并不相等,而是存在一定关系。     

Matrix merging arrangements for the study protein dynamics by time-resolved step-scan Fourier transform infrared spectroscopy and multivariate curve resolution

In this paper, we propose the construction of merging arrangements for combining the information from various runs as a powerful approach to improve the resolution. The bacteriorhodopsin (bR) photocycle has been chosen in this study as an example dealing with the protein dynamics monitored by means of time-resolved step-scan FT-IR spectroscopy. The possibilities of matrix merging are evaluated and results are compared with those from the analysis of individual and augmented matrices. As a conclusion, this strategy provides excellent results for the analysis of this type of time-resolved FT-IR data.     

细菌视紫红质激发态动力学过程的实验与数值分析

本文采用差异吸收光谱法对化学增强型细菌视紫红质的状态变化进行了实验研究.发现在585 nm处明显存在一个稳定的中间过程.从分子动力学和实验出发,提出了一个适用于差异吸收光谱研究方法的数学模型,对菌紫质受激以后的动力学过程进行了模拟与数值分析.     

电场作用下紫膜中细菌视紫红质的圆二色性研究

垂直于测量光束的外电场对紫膜水悬浮液中的细菌视紫红质的圆二色性有很大影响。５０Ｈｚ正弦交流电场作用下产生５６８ｎｍ的正的差圆二色性峰，反向电脉冲串作用下产生５５６ｎｍ左右的负的差圆二色性峰，两峰峰位均未显示有随电压的变化而移动；但是，强度随外加电压的半加而增强；撤去电场后该两峰均即该消失。分析认为，电场下细菌视紫红质中存在柔性结构变化，这种结构变化也可用于存储信息。     

All-trans-N-retinylidenetryptamine Schiff base in surfactant solubilized water pools in heptane—a fluorescence study

All-trns-N-retinylidenetryptamine Schiff base was incorporated into aerosol-OT (AOT, sodium bis(2-ethylhexyl)sulphosuccinate)/heptane reverse micelles. This micellar system was used as a model to study the retinal-tryptophan interactions in retinal proteins. The retinylidene Schiff base remains stable in the presence of reverse micelle-solubilized water pools. Partition coefficient and microviscosity measurements show that the Schiff base is located in the micellar interphase. The results are discussed in terms of the interaction between the retinylidene chromophore and the active site environment of rhodopsin and bacteriorhodopsin. In the present model, the quencher and emitting units are covalently attached, and are separated by two carbon spacer units. The fluorescence emission data obtained for the micelle-intercalated Schiff base chromophore are compared with the fluorescence of the native protein and intermediates in the photochemical cycle of bacteriofhodopsin. A comparison of the data obtained for tryptamine and the Schiff base with the results available for bacteriorhodopsin and bacterioopsin reveals that there is a large degree of quenching on intercalation of the retinylidene chromophore in the vicinity of the fluorophore. Evidence provided by this model suggests that energy transfer to retinal can occur from tryptophan residues located in the retinal pocket in the native protein. Thus the retinylidene unit can act as a quencher of the energy of tryptophan, the nature and extent of which may depend on the conformation and relative orientation of the protein-bound fluorophore.     

Bacteriorhodopsin as an Example of a Light-Driven Proton Pump

Apart from the long known visual pigments, another retinal protein complex exists in nature, viz. bacteriorhodopsin from halobacteria. In contrast to the visual pigments such as the rhodopsins, which act as light sensors in the eye, bacteriorhodopsin actually transforms light energy. This energy conversion is connected with the asymmetric incorporation of bacteriorhodopsin in the lattice structure of the purple membrane which forms patches on the cell surface of halobacteria. Alongside the chlorophyll system, the purple membrane system represents the second light energy conversion principle to be discovered in living nature. Bacteriorhodopsin acts as a light-driven proton pump or as the main component of such a pump system. Absorption of light triggers off a cycle of reactions coupled with the spatially oriented uptake and release of a proton. In the intact cell an electrochemical gradient is thus built up across the cell membrane of the bacterium in which part of the absorbed light energy is stored and which is not dependent upon redox processes as in the case of respiration or photosynthesis. This electrochemical gradient can supply the energy required for ATP synthesis in the cell; a reversible proton-translocating ATPase serves as catalyst system.     

光敏蛋白菌紫质分子及其在光电器件中的应用

紫膜菌紫质是一类新型的光敏蛋白分子,本文在介绍菌紫质分子结构和光致色变特性的基础上,重点讨论了它们在光探测器,全息材料,空间光调制器,光盘,条纹相机等光电器件中的潜在应用。     

Interferometric system for non-destructive testing based on large diameter bacteriorhodopsin films

A system for holographic interferometry using bacteriorhodopsin films as an erasable optical recording medium is presented. Bacteriorhodopsin is a photochromic protein found in archaebacteria. Bacteriorhodopsin films with an aperture of 90×90 mm are used for high-resolution lensless recording (5000 lines/mm). The holograms are recorded in reflection-type geometry in order to achieve a compact design. A frequency-doubled Nd : YVO₄ laser, emitting at 532 nm, is used for recording and incoherent blue light is employed for photochemical erasure. The system is suitable for a variety of different interferometric techniques like double-exposure, time-averaging and real-time interferometry. As an example for the application of the BR-based non-destructive testing system the inspection of ceramic motor valves, made from silicone nitride (Si₃N₄), under mechanical load is reported.