排序方式: 共有74条查询结果,搜索用时 15 毫秒
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用不锈钢/电沉积紫膜薄膜/含水胶(电介质)/钢型菌紫质光电池研究了作用于N-端表面(紫膜外表面)的钾、镁、镧离子对菌紫质光电响应的影响。在所测条件下光电极性均与质子泵方向一致。光电压幅值是离子浓度依赖性的,对钾、镁、镧离子均存在极大值浓度,它们之间有数量级的差异;依赖性曲线趋势和极大值浓度均各自分别与溶液中菌紫质的质子泵效率对阳离子浓度的这种依赖性相一致。不过,光电响应对作用于C-端表面的这些离子不存在上述的浓度依赖性。上述的两种依赖性成相关性说明:电沉积紫膜薄膜中菌紫质的光电响应主要来自质子泵运而非非质子离子的贡献;存在一合适的离子浓度使菌紫质的光电响应有极大值。用质子泵结构域模型和扩散双电层理论对这种依赖性进行的讨论认为:金属阳离子的结合与屏蔽两种效应可以解释这种依赖性。 相似文献
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Thomas B. Woolf 《International journal of quantum chemistry》1998,69(1):105-116
The two-stage model of membrane protein folding predicts that isolated transmembrane α-helices form stably in the bilayer before coming together to form the fully functional protein. Insight into the molecular implications of this model are possible with detailed molecular dynamics calculations. Thirty molecular dynamics simulations of both individual and pairs of α-helices from bacteriorhodopsin were calculated with the CHARMm program. This data base will continue to grow and expand. Already, differences between identical helices in different media and different helices in the same media have been found. The current results are summarized in this contribution. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 105–116, 1998 相似文献
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新型超硬材料β—C3N4的研究进展 总被引:1,自引:0,他引:1
βC3N4材料的研究是继非晶、准晶及C60之后,凝聚态物理与材料科学领域中又一新的研究热点.βC3N4是一种新型假想材料,理论上预言它可能具有可与金刚石比拟甚至更大的体弹性模量和较为特殊的电学及光学性能.现在的研究工作主要集中在高含氮量的CNx薄膜的制备上,已经获得了直径为微米量级的βC3N4的多晶颗粒和原子比N/C>1的薄膜,且由衍射计算出的晶体结构参数与理论计算值基本相符,探索简便易行的合成βC3N4的方法和开发βC3N4的潜在应用将是今后此项研究的主要方向. 相似文献
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对标准菌株Haloterrigena thermotolerans JCM 11050^T,其编码螺旋C至螺旋G的细菌视紫红质(bacteriorhodopsin,BR)蛋白基因(bop基因)片断采用PCR方法进行了扩增,TA克隆并测定了其核苷酸序列.对翻译出的氨基酸序列进行亲水性分析,表明该菌株的BR蛋白与已报道相应序列具有类似的二级结构.蛋白序列聚合比对结果表明,该菌株BR蛋白与Natrinema属的BR蛋白具有一定相似性.在这一Haloterrigena属的标准菌株中证实bop基因,进一步丰富了bop基因资源. 相似文献
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This paper reports, for the first time, that Archaerhodopsin-4 (AR4) could be reconstituted into phospholipid liposomes by self-assembly. AR4 is a new membrane protein isolated from halobacteria H.sp. xz515 in a salt lake of Tibet, China. This is a bacteriorhodopsin (bR) like protein, function as a light-driven proton pump. Experimental measurements verified that similar to bR, AR not only remains its biological activity in pmteoliposome, but also keeps a preferred orientation in self-assembly. 相似文献
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We present a detailed and accurate analysis of low power spatial light modulation characteristics of bacteriorhodopsin (bR) based on nonlinear intensity induced absorption. Amplitude modulation of probe laser read beam transmissions at 410 nm and 640 nm, corresponding to the peak absorption of MII and O states of D96N bR and WT bR respectively, by the modulation laser write beam intensity-induced population changes at 570 nm has been analyzed, considering all intermediate states with both forward and backward transitions in the respective bR photocycles, using the rate equation approach. The SLM characteristics are shown to be sensitive to the normalized small signal absorption coefficient β, rate constants of MII and O intermediate states and the absorption cross-section of the initial B state at the probe wavelength (σBp). There exists an optimum value of β for which maximum percentage modulation can be achieved. It is shown that for extended MII state lifetime of 250 s in D96N bR and O state lifetime of 2.2 s in WT bR, with σBp= 0, 100% modulation of read beam transmissions can be achieved, leading to high dynamic range and sensitivity for low laser write beam intensities of 50 μW/cm2 and 4 mW/cm2 at 570 nm, respectively. 相似文献
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用两套具有不同时间分辨率和激发方式的测量系统对菌紫质(BR)光循环动力学进行了泵浦-探测研究。一套是单次脉冲氙灯闪光诱导样品,另一套采用重复调Q倍频YAG激光,器周期性激发样品。检测光使用He-Ne激光器633nm红光。用雪崩光电二极管和500MHz数字示波器进行信号检测与波形处理,实验结果表明,菌紫质循环周期〈15ms。中间体K→L的时间常数为2μs,L→M的时间常数为50μs,在中间体K之前发 相似文献