Browsing by Author "Morozov, A. N."

Now showing 1 - 5 of 5

GaSe1-xSx Crystals for Teraherz Frequency Range
(2009)
Atuchin, Victor V.
;
Andreev, Yury M.
;
Sarkisov, Sergei Yu.
;
Morozov, A. N.
;
Luo, C. -W.
GaSe1-xSx single crystals has been grown by Bridgman-Stockbarger technique. Structural quality has been evaluated with TEM observation. Terahertz time-domain spectroscopy has been applied for measurements of the frequency-dependent optical constant of doped GaSe crystals as a function of s-content.
Molecular Dynamics insight into the role of tertiary (foldon) interactions on unfolding in Cytochrome c
(2009-06-16)
Tsai, M. Y.
;
Morozov, A. N.
;
Chu, K. Y.
;
Lin, S. H.
;
交大名義發表
Hydrogen exchange experiments reveal the existence of a foldon structure in Cytochrome c. We performed constant temperature Molecular Dynamics simulations of Cytochrome c to investigate the macroscopic behavior of the foldons. The results showed that the tertiary interactions in Cytochrome c play an important role in the stabilization of the N- and C-terminal helices. We also observed the macroscopic behavior of a black foldon in the process of thermal unfolding. Our results support that Cytochrome c folding occurs in accordance with the classical pathway concept of Levinthal. (c) 2009 Elsevier B.V. All rights reserved.
Nonadditive interactions in protein folding: The Zipper model of cytochrome c
(2007-08-01)
Morozov, A. N.
;
Shiu, Y. J.
;
Liang, C. T.
;
Tsai, M. Y.
;
Lin, S. H.
Hydrogen exchange experiments (Krishna et al. in J. Mol. Biol. 359:1410, 2006) reveal that folding-unfolding of cytochrome c occurs along a defined pathway in a sequential, stepwise manner. The simplified zipper-like model involving nonadditive coupling is proposed to describe the classical "on pathway" folding-unfolding behavior of cytochrome c. Using free energy factors extracted from HX experiments, the model can predict and explain cytochrome c behavior in spectroscopy studies looking at folding equilibria and kinetics. The implications of the proposed model are discussed for such problems as classical pathway vs. energy landscape conceptions, structure and function of a native fold, and interplay of secondary and tertiary interactions.
Study of GaSe1-xSx Properties for Terahertz Applications
(2009)
Sarkisov, S. Yu.
;
Andreev, Yu. M.
;
Atuchin, V. V.
;
Morozov, A. N.
;
Kazakov, A. V.
For prospective nonlinear crystals GaSe1-xSx experimental study of second harmonic generation processes of Er3+:YSGG-, CO2- and CO-lasers has been performed, control experiment on difference frequency generation of two lines Of CO2-laser has been realized, the transmission spectra and dispersion of complex refractive indices in terahertz range have been measured.
Thermodynamics of a conformational change using a random walk in energy-reaction coordinate space: Application to methane dimer hydrophobic interactions
(2009-02-21)
Morozov, A. N.
;
Lin, S. H.
;
交大名義發表
;
National Chiao Tung University
A random walk sampling algorithm allows the extraction of the density of states distribution in energy-reaction coordinate space. As a result, the temperature dependences of thermodynamic quantities such as relative energy, entropy, and heat capacity can be calculated using first-principles statistical mechanics. The strategies for optimal convergence of the algorithm and control of its accuracy are proposed. We show that the saturation of the error [Q. Yan and J. J. de Pablo, Phys. Rev. Lett. 90, 035701 (2003); E. Belardinelli and V. D. Pereyra, J. Chem. Phys. 127, 184105 (2007)] is due to the use of histogram flatness as a criterion of convergence. An application of the algorithm to methane dimer hydrophobic interactions is presented. We obtained a quantitatively accurate energy-entropy decomposition of the methane dimer cavity potential. The presented results confirm the previous results, and they provide new information regarding the thermodynamics of hydrophobic interactions. We show that the finite-difference approximation, which is widely used in molecular dynamic simulations for the energy-entropy decomposition of a free energy potential, can lead to a significant error.