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Photochromic Molecule (photochromic + molecule)

Distribution by Scientific Domains
Chemistry50%

Selected Abstracts

Protein Diffusion Probed by the Transient Grating Method with a New Type of Photochromic Molecule,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008
Takeshi Eitoku
A new type of photochromic molecule that can be used for diffusion coefficient (D) measurements of various proteins in solution is described. The absorption spectrum of this molecule is changed upon photoexcitation by the trans,cis isomerization reaction. Target proteins were labeled by this photochromic molecule in the dark and the translational motion of the proteins was detected by the transient grating (TG) method. The TG signal was simple enough to determine D accurately and was stable even for long-time irradiation by the laser light. The TG method using this probe molecule improves many drawbacks of the other techniques. [source]

Deconvolution of femtosecond time-resolved spectroscopy data in multivariate curve resolution.

JOURNAL OF CHEMOMETRICS, Issue 7-8 2010
Application to the characterization of ultrafast photo-induced intramolecular proton transfer
Abstract In femtosecond absorption spectroscopy, deconvolution of the measured kinetic traces is still an important issue as photochemical processes that may possess shorter characteristic times than the time resolution of the experiment are usually considered. In this work, we propose to perform deconvolution of the time-dependent concentration profiles extracted from multivariate curve resolution (MCR) applied to spectrokinetic data. The profiles are fitted with a model function including a description of the instrumental response function (IRF) of the experiment. The method combines the potential benefits of soft-modeling data analysis with the ones of hard-modeling for parameter estimation. The potential of the method is demonstrated first analyzing five synthetic data sets for which IRF of different widths are simulated. It is then successfully applied to resolve femtosecond UV-visible transient absorption spectroscopy data investigating the photodynamics of salicylidene aniline, a photochromic molecule of wide interest. Considering a time resolution of 150,fs for the IRF, a characteristic time of 45,fs is recovered for the first step of the photo-induced process which consists of an ultrafast intramolecular proton transfer. Our results also confirm the existence of an intermediate species with a characteristic time of 240,fs. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Protein Diffusion Probed by the Transient Grating Method with a New Type of Photochromic Molecule,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008
Takeshi Eitoku
A new type of photochromic molecule that can be used for diffusion coefficient (D) measurements of various proteins in solution is described. The absorption spectrum of this molecule is changed upon photoexcitation by the trans,cis isomerization reaction. Target proteins were labeled by this photochromic molecule in the dark and the translational motion of the proteins was detected by the transient grating (TG) method. The TG signal was simple enough to determine D accurately and was stable even for long-time irradiation by the laser light. The TG method using this probe molecule improves many drawbacks of the other techniques. [source]

Dwelling in the dark: procedures for the crystallography of phytochromes and other photochromic proteins

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2009
Jo Mailliet
Crystallization of phytochromes and other photochromic proteins is hampered by the conformational changes that they undergo on exposure to light. As a canonical phytochrome, cyanobacterial Cph1 switches between two stable states upon absorption of red/far-red light. Consequently, it is mandatory to work in darkness from protein purification to crystal cryoprotection in order to ensure complete occupancy of one state or the other. With the simple and inexpensive methods that have been developed, phytochromes and other photochromic molecules can effectively be handled and crystallized, as has been demonstrated by the solution of the three-dimensional structure of the Cph1 sensory module. [source]