Interaction of Ovalbumin with Phospholipids Langmuir−Blodgett Film

Abstract

Interaction of native ovalbumin (OVA) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir-Blodgett monolayer has been studied at the air-water interface. A compressibility study shows the positive association with DPPC. Adsorption kinetics shows that the protein adsorption is a one-step process and the amount of protein adsorbed depends on the concentration of protein at the water subphase. Incorporation of protein into the DPPC layer is surface-pressure dependent. The compressibility study indicates that the DPPC-OVA interaction is hydrophobic in nature and structural reorganization is eminent to adjust the hydrophobic mismatch between DPPC acyl chains and OVA hydrophobic moieties. At higher pressure, OVA tends to squeeze out from the DPPC monolayer. A nanometer scale FE-SEM image confirms this observation. Globular aggregates of protein of dimension 60-80 nm were observed in DPPC-OVA supported film. Steady-state fluorescence spectroscopy suggests that the tryptophan residues of OVA are main emitting species. The blue shift of tryptophan fluorescence in supported film may be due to the tryptophan molecule of protein exposed to the hydrophobic air phase.

Adsorption of pepsin in octadecylamine matrix at air–water interface

“…A slow protein attachment process is also competing here. Similar observations were found for ovalbumin in DPPC, ODA and SA [10,17,20] as well as puroindoline in DPPC and in DPPG monolayer [25].…”

“…The details of experimental processes were similar with our previous experiment described elsewhere [10,17]. For the preparation of pure PEP film, a known amount of aqueous solution of PEP of concentration 1 mg/mL was spread on the water subphase by a microsyringe.…”

“…Numerous methods, such as sol-gel process, self-assembly (SA), Langmuir Blodgett (LB) techniques etc. [9][10][11][12][13][14][15] are proposed for immobilizing proteins in lipid matrices. Among these, the Langmuir and/or Gibbs monolayer studies and subsequent monolayer transfer to solid substrate by LB techniques are the most versatile and convenient techniques to study the protein-lipid interaction at air/water interface for entrapment of protein/enzyme in lipid matrices as well as for designing ultra thin artificial films with biological functions [16].…”

Polyelectrolyte multilayers-modified membrane filter for rapid immunoassay: protein condensation by centrifugal permeation

“…c The dimensions of OVA are 7Â5Â4.5 nm. 23 When one assumes full monolayer coverage, the amount of OVA adsorption was 0.42 and 0.27 mg cm À2 in the end-on and side-on positions, respectively.…”

Synthesis of Amphiphilic Azo‐Anion‐Radical Complexes of Chromium(III) and the Development of Ultrathin Redox‐Active Surfaces by the Langmuir–Schaefer Technique

“…Details of the procedure for cleaning the quartz slides and glass cover-slips have been described elsewhere. [47] Field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) measurements: The surface morphologies of all films lifted from the pure-water subphase at different surface pressures were studied on the nanometer scale by high-resolution field-emission scanning electron microscopy (FE-SEM, model No. : JEOL JSM-6700 F) over the range: 0.5-30 kV with a lateral resolution in the range 2.2-1.2 nm.…”