title: Effect of particle size on conformation and enzymatic activity of EcoRI adsorbed on CdS nanoparticles.
abstract: Better understanding of the interaction between nanoparticles (NPs) and protein is the basis for biological and biomedical applications of NPs. Water-soluble fluorescent CdS NPs have been widely used in the biological and biomedical fields and the study on effect of CdS NPs size on conformation and enzymatic activity of protein might be very important in its application. In this work, the interaction of CdS NPs with different size with type II restriction endonuclease (EcoRI) were investigated by atomic force microscopy, transmission electron microscopy, UV-vis spectroscopy, fluorescence quenching method, CD spectra, laser scanning confocal microscopy and gel electrophoresis. It was found that the equilibrium constant (kD) as well as the cooperativity degree of CdS NPs-EcoRI binding (Hill constant, n) strongly depended on the CdS NPs size. The different curvature of CdS NPs surface could result in different changes of EcoRI conformation. The gel electrophoresis indicated that the decrease in α-helix content more or less affected the activity of EcoRI.
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Song
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhong
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Luo
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 East Nan-Hu Road, Changchun 130033, People's Republic of China.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Sun
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China. Electronic address: lwanggroup@yahoo.com.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D019187:Cadmium Compounds / Q000737:chemistry*; D002942:Circular Dichroism; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry* / Q000378:metabolism*; D057075:Enzyme Assays; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D015246:Deoxyribonuclease EcoRI
keywords: CdS nanoparticles; Conformation change; Cooperativity; EcoRI; Enzymatic activity