Mixed-salt effects on the conformation of a short salt-bridge-forming a helix: A simulation study

doi:10.1103/PhysRevE.89.022717

	Mixed-salt effects on the conformation of a short salt-bridge-forming a helix: A simulation study
	Shen, Hao 1,2; Cheng, Wei 1,2; Zhang, Feng-Shou 1,2,3
刊名	PHYSICAL REVIEW E
	2014-02-21
卷号	89
ISSN号	1539-3755
DOI	10.1103/PhysRevE.89.022717
文献子类	Article
英文摘要	The structure of a single alanine-based ACE-AEAAAKEAAAKA-NH2 peptide in explicit aqueous solutions with mixed inorganic salts (NaCl and KCl) is investigated by using molecular simulations. The concentration of Na+, c(Na)+, varies from 0.0M to 1.0M, whereas the concentration of K+ is 1 - c(Na)+. The simulated peptide is very sensitive to the change of concentration ratio between Na+ and K+. When the concentration ratio between Na+ and K+ is changed from 0.5/0.5, the structure of the peptide becomes loose or disordered. This specific phenomenon is confirmed via checking the changes of helix parameters and mapping the free energy along different coordinates. The higher normalized probability of forming direct and indirect salt bridges between residues Glu7(-) and Lys11(+) and the smallest probability of forming ringlike structures should be responsible for the stabilized helix structure in the 0.5 Na+/0.5 K+ solution. Furthermore, a noticeable conformational transition from an extended helix to an a helix is found in the 0.5 Na+/0.5 K+ solution, where a local ion cloud shows that some Na+ ions in the inner shells are still directly binding with the peptide, while K+ in the outer shells are moving into the inner shells, keeping the peptide in the collapsed state.
资助项目	European Commission[269131]
WOS关键词	MOLECULAR-DYNAMICS SIMULATIONS ; SIDE-CHAIN INTERACTIONS ; ALANINE-BASED PEPTIDES ; HOFMEISTER-SERIES ; POLYPEPTIDE-CHAINS ; INTERNAL-FRICTION ; AQUEOUS-SOLUTIONS ; SURFACE-TENSION ; IONIC-STRENGTH ; ALPHA-HELIX
WOS研究方向	Physics
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000332179900012
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/49787]
专题	中国科学院近代物理研究所
通讯作者	Zhang, Feng-Shou
作者单位	1.Beijing Normal Univ, Coll Nucl Sci & Technol, Minist Educ, Key Lab Beam Technol & Mat Modificat, Beijing 100875, Peoples R China 2.Beijing Radiat Ctr, Beijing 100875, Peoples R China 3.Natl Lab Heavy Ion Accelerator Lanzhou, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Shen, Hao,Cheng, Wei,Zhang, Feng-Shou. Mixed-salt effects on the conformation of a short salt-bridge-forming a helix: A simulation study[J]. PHYSICAL REVIEW E,2014,89.
APA	Shen, Hao,Cheng, Wei,&Zhang, Feng-Shou.(2014).Mixed-salt effects on the conformation of a short salt-bridge-forming a helix: A simulation study.PHYSICAL REVIEW E,89.
MLA	Shen, Hao,et al."Mixed-salt effects on the conformation of a short salt-bridge-forming a helix: A simulation study".PHYSICAL REVIEW E 89(2014).