Light Gating

Nagel G et al (2003) Channelrhodopsin-2, a directly light-gated cation-selective membrane channel. Proc Nat Acad Sci USA 100 13940-13945... 

Laser two-focus velocimetiy is applied in the BIRAL L2F. The measurement volume is formed by focusing two laser beams to two small waists of about 10 pm diameter. The result is a light gate operating with concentrations orders of magnitude greater than possible with the LDV system. Particle velocity is determined by the time it takes the particle to pass from one beam waist to the other. 

Szobota S, Gorostiza P, Del Bene F, Wyart C, Fortin DL, Kolstad KD, Tulyathan O, Volgraf M, Numano R, Aaron HL, Scott EK, Kramer RH, Flannery J, Baier H, Trauner D, Isacoff EY. Remote control of neuronal activity with a light-gated glutamate receptor. Neuron 2007 54 535-545. 

Sineshchekov and coworkers could show the direct involvement of both proteins in photoperception (50, 63). Action spectroscopy with knock-down mutants revealed a maximum sensitivity for ChRl at 500 and 470 nm for ChR2. Photophobic responses were impaired by reduction in ChR content while the involvement in phototaxis is still unclear. Chlamydomonas rhodopsins are light-gated ion channels. While the highest conductance is for H -ions the conductance for calcium plays the dominant role under physiological conditions. 

Light-gated catalysis based on photocaged and photoswitchable systems also fascinates chemists.The and (7 ,7 )-( )/(Z)-isomers of the... 

A light-gated saccharide sensor 31 has been studied by Shinmori et al When the azobenzene unit is switched from the more stable transconformation to the thermodynamically unfavorable m-isomer by photoirradiation, the system displays high o-glucose and o-allose selectivity. A cyclic 1 1 complex forms between the saccharide and the dye in its m-geometry and explains the enhanced binding. 

Figure 29 Schematic structural representation of light-gated stop-go (CBPQT) bistable rotaxane. (Reproduced from Ref. 60. American Chemical Society, 2009.)...

Shinmori et al. have synthesized a diboronic acid saccharide receptor bearing a photoresponsive azobenzene group, 51 that was used as a light-gated saccharide sensor [119]. When the azobenzene unit is switched by photoirradiation, from the more stable trans-conformation to the thermodynamically unfavorable cis-isomer, it shows high D-glucose and D-allose selectivity. The formation of cyclic 1 1 complexes between saccharide and the dye in its cis-geometry explains the selectivity order. 

Figure 4.14 Schematic representation of the light-gated nanofluidic diode system at different pH values.

Shinmori has synthesised a diboronic acid-saccharide receptor bearing a photoresponsive azobenzene group 161, which was used as a light-gated saccharide sensor. When the azobenzene unit is switched by photoirradiation... 

M.A. Duguay, J.W. Hansen An ultrafast light gate. Appl. Phys. Lett. 

Shinmori, H., Takeuchi, M., and Shinkai, S., A novel light-gated sugar receptor, which shows high glucose selectivity, /. Chem. Soc., Perkin Trans. 2, 847,1998. 

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