在通道rhodopsin的活跃中心的含水结网
Shota Ito1, Hideaki E Kato, Reiya Taniguchi
1Department of Frontier Materials, Nagoya Institute of Technology , Showa-ku, Nagoya 466-8555, Japan.
Journal of the American Chemical Society
|February 12, 2014
概括
道罗多普辛 (Channelrhodopsin) 是一种光离子通道,其活性中心有一个独特的水网络. 这一发现,使用FTIR光谱学,揭示了与其他微生物罗多素的差异,并影响了光遗传学.
科学领域:
- 生物物理学的生物物理.
- 视觉遗传学 视觉遗传学
- 结构生物学 结构生物学
背景情况:
- 道罗多普辛 (ChR) 是一个光离子通道,对光遗传学至关重要.
- 微生物罗多素,如archaerhodopsin和bacteriorhodopsin,可以作为光驱动的离子.
- 罗多普辛离子运输机制受到视网膜染色体附近的水分子的影响.
研究的目的:
- 为了研究与蛋白质结合的水分子在道罗多普辛的功能中的作用.
- 将CHR的水网络与其他微生物和动物罗多普辛的水网络进行比较.
主要方法:
- 低温富里埃变换红外光谱 (FTIR) 在77K.
- 对一种仿制的CHR蛋白 (CHR1螺旋A-E和CHR2螺旋F-G) 的分析.
主要成果:
- 与其他微生物 (2-6) 和动物 (6-8) 罗多普辛相比,CHR的活性中心含有更多的水分子 (9次振动).
- 在CHR中质子化的视网膜希夫基直接与对子 (Glu162) 相互作用.
- 在CHR的活跃中心周围发现了一个独特的结网络.
结论:
- 碳化合物的独特的水网和直接的希夫基-对立体相互作用使其离子运输机制有所不同.
- 这些发现提供了关于CHR作为光门离子通道功能的结构基础的见解.
- 该研究强调了水分子在罗多普辛功能和光遗传学应用中的重要性.
相关概念视频
Channel Rhodopsins
2.5K
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
2.5K
The Antenna Complex
6.9K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
6.9K
The Photochemical Reaction Center
4.4K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.4K
G-Protein Gated Ion Channels
5.5K
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory...
Sensory...
5.5K
Ligand Binding Sites
11.9K
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
11.9K
Introduction to Chemical Bonds
10.0K
Chemical Bonds
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
10.0K


