Characterization of hybrid bilayer membranes on silver electrodes as biocompatible SERS substrates to study membrane-protein interactions.
Hybrid bilayer lipid membranes (HBMs) were built on roughened silver electrodes exhibiting surface-enhanced Raman scattering (SERS) activity. The HBM consisted of a first layer of octadecanethiol (ODT) directly bound to the electrode surface, on which a second layer of 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) was obtained by self-assembled phospholipid vesicle fusion. The electrochemical properties of the HBM were investigated in situ by cyclic voltammetry (CV), AC voltammetry and electrochemical impedance spectroscopy (EIS). The results indicate that our HBMs are well-formed, and their insulating properties are comparable to those observed for HBM supported by smooth metal substrates. The interaction between the bilayer and the human enzyme cytochrome P450 2D6 (CYP2D6) was investigated. Surface-enhanced resonance Raman scattering (SERRS) measurements in combination with AC and EIS, performed on the same electrode sample, proved that the CYP2D6 is immobilized on the HBM without evident alterations of its active site and without significant perturbations of the bilayer architecture. This study yields novel insights into the properties of HBMs built on roughened surfaces, providing in situ electrochemical characterization of a substrate which is suitable for studying peripheral membrane proteins with SERRS spectroscopy.
Millo
Diego
D
Laser Centre, Analytical Chemistry and Applied Spectroscopy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Bonifacio
Alois
A
Moncelli
Maria Rosa
MR
Sergo
Valter
V
Gooijer
Cees
C
van der Zwan
Gert
G
D001672:Biocompatible Materials / Q000737:chemistry; D019389:Cytochrome P-450 CYP2D6 / Q000737:chemistry / Q000378:metabolism; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D011485:Protein Binding; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
D001672:Biocompatible Materials; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010713:Phosphatidylcholines; D010743:Phospholipids; D013438:Sulfhydryl Compounds; C055360:n-octadecyl mercaptan; C021016:1,2-diphytanoylphosphatidylcholine; D012834:Silver; D019389:Cytochrome P-450 CYP2D6