Fabrication of avidin single molecular layer on silicon oxide surfaces and formation of tethered lipid bilayer membranes

Abstract

Single molecular layer of avidin is fabricated on an atomically flat SiO2 surface and characterized by atomic force microscopy (AFM) and infrared reflection absorption spectroscopy. Immobilization of avidin is performed as follows; i) ester-modification of the surface by silane-coupling agent, ii) carboxylation by hydrolysis in HCl and iii) amide bonding between the surface-COOH and-NH2 in avidin molecules. Large dome structures (∼60 nm height) are formed after the ester-modification, but an atomically flat surface is obtained after the hydrolysis reaction. AFM topographs and function-recognizing images show that the each of avidin molecules adsorbs as a single molecule and retains the biotin-binding activity. Formation of a tethered bilayer membrane of a biotinylated phospholipid on the avidin layer is also described.

Substrate Effects on the Formation Process, Structure and Physicochemical Properties of Supported Lipid Bilayers

“…Dewa et al extensively studied the diffusion properties of bacterial photosynthetic membrane proteins, light-harvesting complex 2 (LH2) and light-harvesting core complex (LH1-RC), in SLBs and tethered bilayers by FRAP [ 70 , 118 , 119 ]. The tethered bilayer of DOPC containing 1% biotinyl dioleoylphosphatidylethanolamine (N-biotinyl-DOPE) is prepared on an avidin-modified glass cover slip [ 120 , 121 ]. Proteoliposomes of LH1-RC and LH2 are prepared for the reconstruction of LH1-RC and LH2 into the SLB and tethered bilayer.…”

“…The gA aggregates show different morphology in a tethered lipid bilayer ( Figure 5 c). In the tethered bilayer of DPPC + N-biotinyl-DOPE + gA (99:1:1) on avidin-modified SiO 2 /Si [ 120 , 121 ], there is a clear separation between the gA-free DPPC-SLB region (I in Figure 5 c) and the gA-incorporated region, including depletions (II in Figure 5 c). Only the dot-like depletion is observed in the region II, and the string-like depletion, which appears on mica ( Figure 5 a), is not observed at the boundary between the regions I and II.…”

Label-free electrical detection of pyrophosphate generated from DNA polymerase reactions on field-effect devices

“…Similar procedures have been reported to control avidin orientation on surfaces and bind one biotinylated molecule per avidin binding site. 30 …”

Imaging of Chemical Reactions Using a Terahertz Chemical Microscope

“…Figure 8a is a cross-sectional schematic of the sensing plate with antibodies on the surface of the sensing plate and Figure 8b is a photograph of the solution wells filled with the antigens. The antibodies were immobilized on the surface of the sensing plate by a covalent binding method [27]. First, the SiO 2 thin film surface was modified with ester groups using 2-(carbomethoxy)ethyltri-chlorosilane (CMETS, Fujifilm Wako Pure Chemicals, Tokyo, Japan).…”