• BMB Reports
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• v.36 no.4
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• pp.359-366
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• 2003

The effects of zinc on arginine kinase and its collapsed-state intermediate were studied. Both arginine kinase and the collapsed-state intermediate were inactivated in the presence of zinc, following a biphasic kinetic course. The corresponding apparent rate constants of inactivation at different zinc concentrations and conformational changes in the presence of 0.5 mM zinc were obtained. The conformational changes of arginine kinase and the collapsed-state intermediate were followed by fluorescence spectra and circular dichroism spectra. Comparison of the results for arginine kinase and the collapsed-state intermediate showed that the collapsed-state intermediate was more susceptible to zinc, which indicated that the collapsed-state intermediate was more flexible and unstable than arginine kinase. The special structure of arginine kinase might explain these diverse phenomena.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.33-40
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• 2004

Thermodynamic properties of ubiquitin transient folding intermediate were studied by measuring folding kinetics in varying temperatures and denaturant concentrations. Through quantitative kinetic modeling, the equilibrium constant, hence folding free energy, between unfolded state and intermediate state in several different temperatures were calculated. Using these values, the thermodynamic parameters were estimated. The heat capacity change $({\Delta}C_p)$ upon formation of folding intermediate from unfolded state were estimated to be around 80% of the overall folding reaction, indicating that ubiquitin folding intermediate is highly compact. At room temperature, the changes of enthalpy and entropy upon formation of the intermediate state were observed to be positive. The positive enthalpy change suggests that the breaking up of the highly ordered solvent structure surrounding hydrophobic side-chain upon formation of intermediate state. This positive enthalpy was compensated for by the positive entropy change of whole system so that formation of transient intermediate has negative free energy.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1509_1510
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• 2009

This paper presents the design and simulation results of ohmic contact RF MEMS silicon switch with a high isolation at high frequencies along with the position of a contact part, initial off-state and intermediate off-state including the state where a contact part is placed right over a signal line of coplanar waveguide (CPW). The ohmic contact part is connected with comb drives made of high resistivity single crystalline silicon. The released contact part is $30{\mu}m$ apart from the edge of signal line on the glass substrate along the lateral direction (x-direction) at initial off-state. The electrostatic force of the comb electrode creates the x-directional movement thus initial state is converted to the intermediate off-state. The initial off-state of the switch results in isolations of -31 dB, -24 dB and reflections of -0.45 dB, -0.67 dB at 50 GHz and 110 GHz, respectively. It shows the isolation degradation when the contact part moves right over the signal line of CPW like an initial off-state of a conventional MEMS switch. The isolations and reflections are -31 dB, -24 dB and -0.50 dB, -1.31 dB at 50 GHz and 110 GHz, respectively at the intermediate off-state.

• Journal of Photoscience
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• v.12 no.2
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• pp.63-66
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• 2005

The azomethine ylide forming photoreaction has been explored by probing the excited state chemistry of several N-trimethylsilylmethyl substituted cyclic and acyclic imides and amide analogs. N-[(Trimethylsilyl)methyl]-N-mesylbenzamide (5) undergoes the excited state C to O silyl migration reaction to produce azomethine ylide intermediate 13. This ylide undergoes electrocyclization to form transient aziridine intermediate 14 which react further by ring opening to generate N-phenacylamine product 10. On the other hand, photolysis of N-[N-mesyl-N-(trimethylsilyl)methyl]aminoethyl-N-mesylbenzamide (8) brings about desilylation resulting in the production of dimer 17.

• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1311-1327
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• 2016

We propose a multi-state model for analyzing semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the 'illness-death model', which composes three states, such as 'healthy', 'diseased', and 'dead'. The state of 'diseased' can be considered as an intermediate event. Two more states are added into the illness-death model to describe missing events caused by a loss of follow-up before the end of the study. One of them is a state of 'LTF', representing a lost-to-follow-up, and the other is an unobservable state that represents the intermediate event experienced after LTF occurred. Given covariates, we employ the Cox proportional hazards model with a normal frailty and construct a full likelihood to estimate transition intensities between states in the multi-state model. Marginalization of the full likelihood is completed using the adaptive Gaussian quadrature, and the optimal solution of the regression parameters is achieved through the iterative Newton-Raphson algorithm. Simulation studies are carried out to investigate the finite-sample performance of the proposed estimation procedure in terms of the empirical coverage probability of the true regression parameter. Our proposed method is also illustrated with the dataset adapted from Helmer et al. (2001).

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2877-2883
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• 2010

The folding kinetics of $WT^*$ ubiquitin variant with valine to alanine mutation at sequence position 26 (HubWA) was studied by stopped-flow fluorescence spectroscopy. While unfolding kinetics showed a single exponential phase, refolding reaction showed three exponential phases. The semi-logarithmic plot of urea concentration vs. rate constant for the first phase showed v-shape pattern while the second phase showed v-shape with roll-over effect at low urea concentration. The rate constant and the amplitude of the third phase were constant throughout the urea concentrations, suggesting that this phase represents parallel process due to the configurational isomerization. Interestingly, the first and second phases appeared to be coupled since the amplitude of the second phase increased at the expense of the amplitude of the first phase in increasing urea concentrations. This observation together with the roll-over effect in the second folding phase indicates the presence of intermediate state during the folding reaction of HubWA. Quantitative analysis of Hub-WA folding kinetics indicated that this intermediate state is on the folding pathway. Folding kinetics measurement of a mutant HubWA with hydrophobic core residue mutation, Val to Ala at residue position 17, suggested that the intermediate state has significant amount of native interactions, supporting the interpretation that the intermediate is on the folding pathway. It is considered that HubWA is a useful model protein to study the contribution of residues to protein folding process using folding kinetics measurements in conjunction with protein engineering.

• Journal of the Korean Chemical Society
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• v.57 no.2
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• pp.216-220
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• 2013

The hydroalumination of cyclopropane has been investigated using the B3LYP density functional method employing several split-valence basis sets. It is shown that the reaction proceeds via an intermediate weakly bound complex and a four-centered transition state. Calculations at higher levels of theory were also performed at the geometries optimized at the B3LYP level, but only slight changes in the barriers were observed. Structural parameters for the transition state are also reported.

• Journal of Photoscience
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• v.9 no.2
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• pp.134-137
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• 2002

PYP consists of a water-soluble apoprotein and 4-hydroxycinnamyl chromophore bound to Cys69 via thiolester linkage, Upon absorption of a photon, the photocycle is initiated, leading to formation of several photo-intermediates. Among them, M intermediate is important to understand the signal transduction mechanism of PYP, because it is a putative signaling state. As well known, the dynamics of a protein is closely correlated with the occurrence of its function. Here we report the results of IO ns molecular dynamics (MD) simulation for the M intermediate in aqueous solution and discuss the characteristic feature of this state from a viewpoint of structural fluctuation.

• Journal of Magnetics
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• v.4 no.3
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• pp.102-106
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• 1999

Ce exhibits the intermediate valence (IV) state both as an element and in its compounds. In the present review characteristic behavior of the materials showing the IV state are described. Then the methods of producing this state : the application of the external pressure, temperature and magnetic field as well as the alloying are being discussed. An identification of the IV state is frequently not a simple goal and the best results can be obtained using a combination of various independent methods. Particular attention is paid to the X-ray spectroscopy, lattice parameters and the magnetic properties. As the examples of the IV state in the Ce compounds the properties of following materials are reported : CeRhSb, $CeCu_5In_7, CeAg_6In_6, Sc_{1-x}Ce_xFe_4Al_8 $and for comparison Sc1-xYbxFe4Al8.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.84.2-84.2
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• 2014

The intermediate polar V1323 Her = RXS J180340.0+401214 returned from its faint state 19.4-20.5 mag (mean brightness during the run, the instrumental system close to R or clear filter) (vsnet-alert 16958). On March 1, 2014, the brightness was 17.50 (clear filter) and next night 17.8 (R). During previous observations on January 24, the object was 19.6. We reported this findings to vsnet-alert 16958 and to The Astronomer's Telegramm (ATel #5944). The characteristics of the runs obtained before/after a switch between the high and low states will be presented.