Study on the effect of cosolvent in peptide solution and the electrostatic effect of protein conformation = 펩타이드 용액에서의 공용매 효과와 단백질 구조에 미치는 정전기 효과에 대한 연구

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 292
  • Download : 0
We have performed molecular dynamics (MD) simulations at 300 K on the tricomponent solution containing tripeptide, cosolvent and water molecules to investigate the structural and energetic effects of cosolvents on the peptide and water molecules. We use the glycerol or urea molecule as cosolvent and Gly-Ala-Phe (GAF) as tripeptide in each simulation. The concentration of cosolvent is adjusted to 6~7V% of water. We have also carried out the MD simulations on the two component solution without tripeptide (GAF), i.e., only urea or glycerol molecules, to compare with the above system. We analyze the structural and dynamic change of the tripeptide by the torsional angle distribution and the root-mean-square (RMS) fluctuation. The interactions between all constituent molecules are analyzed by their hydrogen-bonding characteristics. We examine the water structure through hydrogen-bond, the distribution of energies and hydrogen-bonded circular networks, ring. Cosolvent-induced conformational changes occur in the Ala residue in urea solution. The residue, Ala, interacts with urea molecules substituted for water molecules through hydrogen-bond. The water structure around the peptide is slightly more ordered in glycerol solution where glycerol is excluded in the vicinity of peptide. In order to examine in detail the effect of ionizable residues on the stability of α-helical structure, we have performed molecular dynamics simulation on melittin under the controlled pH with macroscopic dielectric model. We simulate at +3-charged, +6-charged and totally uncharged states of melittin, respectively. From these calculations, we obtain various conformational properties such as helical contents, torsion angle trajectories, temperature factors and end-to-end distance. +3-charged state correponding to basic pH range shows the most stable structure. Our analysis conclude that helix is least stable at neutral pH including six positively charged residues and helicity increases as pH ap...
Advisors
Jhon, Mu-Shik전무식
Description
한국과학기술원 : 화학과,
Publisher
한국과학기술원
Issue Date
1995
Identifier
101852/325007 / 000925002
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 화학과, 1995.8, [ viii, 85 p. ]

Keywords

Cosolvent Effect; Electrostatic Effect; Protein Conformation; Molecular Dynamics Simulation; Additives; 첨가제; 공용매 효과; 정전기 효과; 단백질 구조; 분자 동력학시뮬레이션

URI
http://hdl.handle.net/10203/31420
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=101852&flag=dissertation
Appears in Collection
CH-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0