title: Conformation change of horseradish peroxidase in lipid membrane.
abstract: The electrochemical behavior of horseradish peroxidase (HRP) in the dimyristoyl phosphatidylcholine (DMPC) bilayer on the glassy carbon (GC) electrode was studied by cyclic voltammetry. The direct electron transfer of HRP was observed in the DMPC bilayer. Only a small cathodic peak was observed for HRP on the bare GC electrode. The electron transfer of HRP in the DMPC membrane is facilitated by DMPC membrane. UV-Vis and circular dichroism (CD) spectroscopy were used to study the interaction between HRP and DMPC membrane. On binding to the DMPC membrane the secondary structure of HRP remains unchanged while there is a substantial change in the conformation of the heme active site. Tapping mode atomic force microscopy (AFM) was first applied for the investigation on the structure of HRP adsorbed on supported phospholipid bilayer on the mica and on the bare mica. HRP molecules adsorb and aggregate on the mica without DMPC bilayer. The aggregation indicates an attractive interaction among the adsorbed molecules. The molecules are randomly distributed in the DMPC bilayer. The adsorption of HRP in the DMPC bilayer changes drastically the domains and defects in the DMPC bilayer due to a strong interaction between HRP and DMPC films.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, China.
authors.forename: Jilin
authors.initials: J
authors.lastname: Tang
authors.forename: Junguang
authors.initials: J
authors.lastname: Jiang
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Song
authors.forename: Zhangquan
authors.initials: Z
authors.lastname: Peng
authors.forename: Zhengyan
authors.initials: Z
authors.lastname: Wu
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D001665:Binding Sites; D019281:Dimerization; D004134:Dimyristoylphosphatidylcholine; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D006735:Horseradish Peroxidase / Q000737:chemistry*; D008051:Lipid Bilayers; D018625:Microscopy, Atomic Force; D010084:Oxidation-Reduction; D011487:Protein Conformation; D013057:Spectrum Analysis
chemical_list: D008051:Lipid Bilayers; D006735:Horseradish Peroxidase; D004134:Dimyristoylphosphatidylcholine