Sheng-Hsien Lin

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Single-molecule manipulation techniques have enabled the characterization of the unfolding and refolding process of individual protein molecules, using mechanical forces to initiate the unfolding transition. Experimental and computational results following this approach have shed new light on the mechanisms of the mechanical functions of proteins involved(More)
This article reviews from both theoretical and numerical aspects three non-equivalent complete second-order formulations of quantum dissipation theory, in which both the reduced dynamics and the initial canonical thermal equilibrium are properly treated in the weak system-bath coupling limit. Two of these formulations are rather familiar as the time-local(More)
Equilibrium unfolding behaviors of cytochrome c and lysozyme induced by the presence of urea (0-10 M) as well as changes in temperature (295-363 K) or pH (1.8-7) are examined via small-angle x-ray scattering and spectroscopic techniques, including circular dichroism and optical absorption. Denaturant and temperature effects are incorporated into the free(More)
The dynamics of the excited-state intramolecular proton-transfer (ESIPT) reaction of quinoline-pyrazole (QP) isomers, designated as QP-I and QP-II, has been investigated by means of time-dependent density functional theory (TDDFT). A lower barrier has been found in the potential energy curve for the lowest singlet excited state (S1) along the(More)
The local and global structural changes of cytochrome c induced by urea in aqueous solution have been studied using X-ray absorption spectroscopy (XAS) and small-angle X-ray scattering (SAXS). According to the XAS result, both the native (folded) protein and the unfolded protein exhibit the same preedge features taken at Fe K-edge, indicating that the(More)
We have introduced the satellite hole spectral method to examine the binding sites of 3,3′-diethyloxadicarbocyanine cation (DODC+) to various guanine-rich oligonucleotides. The satellite hole patterns along with normal mode calculations allow us to determine the interaction of DODC+ with a dimeric hairpin quadruplex formed by sequence d(G4T4G4). Our results(More)
The excited-state orientation hydrogen-bonding dynamics, and vibronic spectra of isoquinoline (IQ) and its cationic form IQc in water have been investigated at the time-dependent density functional theory quantum chemistry level plus Franck-Condon simulation and interpretation. The excited-state orientation hydrogen bond strengthening has been found in(More)
Superexcited states (SESs) of oxygen molecules and their neutral dissociation processes have been studied both experimentally and theoretically using intense femtosecond laser. We find that at the laser intensity of approximately 2 x 10(14) W/cm(2), ultrashort laser pulse causes neutral dissociation of oxygen molecule by way of SESs. The dissociation(More)
Stochastic nature due to distance and energy fluctuations of single protein molecules involved in electron-transfer (ET) reactions is studied. Distance fluctuations have been assumed previously for causing the slow fluctuations in the ET rates between a donor-acceptor pair constrained to a native protein. Although the observed t(-1/2) power law can be(More)