دورية أكاديمية

Periodic and stochastic thermal modulation of protein folding kinetics.

التفاصيل البيبلوغرافية
العنوان: Periodic and stochastic thermal modulation of protein folding kinetics.
المؤلفون: Platkov, Max, Gruebele, Martin
المصدر: Journal of Chemical Physics; 7/21/2014, Vol. 141 Issue 3, p1-8, 8p, 1 Diagram, 1 Chart, 5 Graphs
مصطلحات موضوعية: STOCHASTIC analysis, PROTEIN folding kinetics, CHEMICAL reactions, QUANTUM perturbations, WAVE analysis, SIGNAL processing
مستخلص: Chemical reactions are usually observed either by relaxation of a bulk sample after applying a sudden external perturbation, or by intrinsic fluctuations of a few molecules. Here we show that the two ideas can be combined to measure protein folding kinetics, either by periodic thermal modulation, or by creating artificial thermal noise that greatly exceeds natural thermal fluctuations. We study the folding reaction of the enzyme phosphoglycerate kinase driven by periodic temperature waveforms. As the temperature waveform unfolds and refolds the protein, its fluorescence color changes due to FRET (Förster resonant Energy Transfer) of two donor/acceptor fluorophores labeling the protein. We adapt a simple model of periodically driven kinetics that nicely fits the data at all temperatures and driving frequencies: The phase shifts of the periodic donor and acceptor fluorescence signals as a function of driving frequency reveal reaction rates. We also drive the reaction with stochastic temperature waveforms that produce thermal fluctuations much greater than natural fluctuations in the bulk. Such artificial thermal noise allows the recovery of weak underlying signals due to protein folding kinetics. This opens up the possibility for future detection of a stochastic resonance for protein folding subject to noise with controllable amplitude. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Chemical Physics is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
قاعدة البيانات: Complementary Index