6th Mini-Symposium on Liquids
２０１２年６月２３日（土）
タイトル一覧
<<< Time Table >>> (最近の更新 4/29/2012)
Poster Session 1 / Coffee (10:00~11:30)
Poster Presentations.
Lunch (11:30~12:50)
0:Ryo Akiyama (Kyushu Univ., Japan)
Opening Remarks
(12:50~13:00)
1:Takahiro Koishi (古石 貴裕) (Fukui Univ., Japan)
Title: Molecular Dynamics Simulation of Droplets on Nanopillared Surface
(ナノスケールの凹凸表面における水滴の分子動力学シミュレーション)
(13:00~13:30)
2:Hiroshi Onishi (大西 洋) (Kobe Univ., Japan)
Title: Interfacial Liquids Visualized by Frequency-Modulation AFM
(固液界面液体の周波数変調原子間力顕微鏡を用いた研究)
(13:30~14:00)
3:Yoji Kubota (久保田 陽二) (Kyushu Univ., Japan)
Title: Fast Dielectric Relaxation of Water around an Ion
(イオン周りで見られる水の速い誘電緩和)
(14:00~14:30)
Poster Preview (14:30~15:00?)
Poster Session 2 / Coffee (15:00~16:30)
Poster Presentations.
4:Akira Kakugo (角五 彰) (Hokkaido Univ., Japan)
Title: Dynamic self-organization and polymorphism of microtubule assembly through active interactions with kinesin
(生体分子モーターキネシン上で動的に自己組織化する微小管集合体の多形構造)
(16:30~17:00)
5:Ryuhei Harada (原田 隆平) (RIKEN, Japan)
Title: Hydration and Protein Stability under Molecular Crowding Environments
(分子混雑環境における水和構造と蛋白質の構造安定性)
(17:00~17:30)
6:Jian-Ren Shen (沈 建仁) (Okayama Univ., Japan)
Title: Crystallization and crystal structure of photosystem II, a membrane-protein complex catalyzing light-induced water-splitting in photosynthesis
(光合成において光駆動水分解を触媒する光化学系II膜タンパク質の結晶化と結晶構造)
(17:30~18:00)
<<< Abstract >>>
Takahiro Koishi (古石 貴裕) (Fukui Univ., Japan)
Title: Molecular Dynamics Simulation of Droplets on Nanopillared Surface
(ナノスケールの凹凸表面における水滴の分子動力学シミュレーション)
Abstract:
Molecular dynamics simulations of water droplets on a pillared surface
were performed to investigate the equilibrium state of the droplets in
nano-scale. Typically, liquid droplets on pillared surface exhibit two
equilibrium states: the Wenzel state in which liquid droplets are in
full contact with the structured surface; and the Cassie state in
which liquid droplets are in contact with peaks of the pillared
surface. We estimated the height of the free energy barrier separating
the two states using impinging droplets. It was found that the height
of the free energy barrier was 0.334 kJ/mol for the surface in which
the pillar height was 1.34 nm. We also calculated the internal
pressure profile of the impinging droplet to reveal the microscopic
property of it.
Hiroshi Onishi (大西 洋) (Kobe Univ., Japan)
Title: Interfacial Liquids Visualized by Frequency-Modulation AFM
(固液界面液体の周波数変調原子間力顕微鏡を用いた研究)
Abstract:
Liquid-solid interfaces play an important role in artificial devices and biological tissues. Scanning tunneling microscopes operated in electrochemical environments have provided much knowledge about the topography of metals and chemisorbed molecules buried in liquids. Our knowledge is still limited about the structure of liquids facing to solids. Frequency-modulation atomic force microscopy (FM-AFM) is a promising tool to observe the solid topography and the liquid structure at interfaces. The cantilever with a tip is resonantly oscillated and the shift of the resonance frequency represents liquid-induced force pushing or pulling the tip.
Yoji Kubota (久保田 陽二) (Kyushu Univ., Japan)
Title: Fast Dielectric Relaxation of Water around an Ion
(イオン周りで見られる水の速い誘電緩和)
Abstract:
We have calculated dielectric relaxation of water around an ion using
molecular dynamics simulations.
The collective dielectric relaxation in the hydration shells around the
ion is faster than that of the bulk, whereas the reorientational motion
of the individual water does not have the fast component.
The ratio of the relaxation time between the fast component in the
nearest hydration shell and the bulk is about 60 - 80 %. This calculated
ratio is consistent with that between the hyper-mobile water and bulk
water in the experiments for alkali halide aqueous solution.
The self term of the time-correlation function shows slowly relaxation.
These results shows that the contribution of the cross-term is important
for the analysis of the hyper-mobile water.
Akira Kakugo (角五 彰) (Hokkaido Univ., Japan)
Title: Dynamic self-organization and polymorphism of microtubule assembly through active interactions with kinesin
(生体分子モーターキネシン上で動的に自己組織化する微小管集合体の多形構造)
Abstract:
In this study, we show that the energy-dissipative active self-assembly of microtubules (MTs) via a kinesin-based motility
system produces various MT assemblies such as bundle-,network-, and ring-shaped structures depending on the initial
conditions. Structural polymorphism of the MT assembly is depicted through phase diagrams, and morphogenesis of the MT
assembly is discussed based on the following factors; binding force between MTs and motility-driving force from kinesins.
This study provides new insights into the energy-dissipative dynamic self-organization of biological systems.
Ryuhei Harada (原田 隆平) (RIKEN, Japan)
Title: Hydration and Protein Stability under Molecular Crowding Environments
(分子混雑環境における水和構造と蛋白質の構造安定性)
Abstract:
The effect of protein crowding on the structure and dynamics of water was examined from explicit solvent molecular dynamics simulations of a series of protein G and protein G/villin systems at different protein concentrations. Hydration structure was analyzed in terms of radial distribution functions, three-dimensional hydration sites, and preservation of tetrahedral coordination. Analysis of hydration dynamics focused on self-diffusion rates and dielectric constants as a function of crowding. The results show significant changes in both structure and dynamics of water under highly crowded conditions. The structure of water is altered mostly beyond the first solvation shell. Diffusion rates and dielectric constants are significantly reduced following linear trends as a function of crowding reflecting highly constrained water in crowded environments. The reduced dynamics of diffusion is expected to be strongly related to hydrodynamic properties of crowded cellular environments while the reduced dielectric constant under crowded conditions has implications for the stability of biomolecules in crowded environments. The results from this study suggest a prescription for modeling solvation in simulations of cellular environments.
Jian-Ren Shen (沈 建仁) (Okayama Univ., Japan)
Title: Crystallization and crystal structure of photosystem II, a membrane-protein complex catalyzing light-induced water-splitting in photosynthesis
(光合成において光駆動水分解を触媒する光化学系II膜タンパク質の結晶化と結晶構造)
Abstract:
Photosystem II is a huge membrane-protein complex consisting of 19 subunits with a total molecular mass of 350 kDa. We have succeeded in obtaining the crystals of this complex that diffracted to 1.9 Å resolution, and analyzed its structure. The crystallization processes and structure of the complex will be briefly introduced, followed by discussions on roles of water molecules and hydrogen-bond networks in the catalytic water-splitting reaction.
6th Mini-Symposium on Liquids 準備委員会（甲賀、秋山）
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