Building a novel vitronectin assay by immobilization of integrin on calixarene monolayer

Talanta. 2008 Mar 15;75(1):99-103. doi: 10.1016/j.talanta.2007.10.045. Epub 2007 Nov 7.

Abstract

Membrane proteins possess significant hydrophobic domains and are likely to deplete their native activity immobilized on the solid surface relative to those occurring in a membrane environment. To investigate an efficient immobilization method, calix[4]crown-ether monolayer as an artificial protein linker system was constructed on the gold surface and characterized by Fourier transform infrared reflection absorption spectroscopy (FTIR-RAS), atomic force microscopy (AFM) and cyclic voltammetry (CV). Integrin alpha(v)beta3 was functionally immobilized onto the monolayer and the integrin-vitronectin interaction was investigated by surface plasmon resonance (SPR). It was found that calix[4]crown-ether was assembled as a monolayer on the gold surface. Orientation and accessibility of integrin alpha(v)beta3 was assessed by sensitive binding of its natural ligand, vitronectin at pg mL(-1) level. Moreover, surface coverage of integrin layer and thickness calculated through SPR curve simulation verified that integrin layer was a monolayer in activated form. In combination with the SPR method, this calix[4]crown monolayer provided a reliable and simple experimental platform for the investigation of isolated membrane proteins under experimental conditions resembling those of their native properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calixarenes / chemistry*
  • Electrochemistry
  • Integrin alphaVbeta3 / chemistry*
  • Microscopy, Atomic Force
  • Molecular Structure
  • Spectroscopy, Fourier Transform Infrared
  • Surface Plasmon Resonance / methods
  • Vitronectin / chemistry*

Substances

  • Integrin alphaVbeta3
  • Vitronectin
  • Calixarenes