Protein interactions with model chromatographic stationary phases constructed using self-assembled monolayers

J Sep Sci. 2005 Mar;28(5):483-91. doi: 10.1002/jssc.200301667.

Abstract

Model surfaces representative of chromatographic stationary phases were developed by immobilising an homologous series (C2-C18) of n-alkylthiols, mixed monolayers of C4/C18 and thioalkanes with alcohol, carboxylic acid, amino and sulphonic acid terminal groups onto a flat, silver-coated glass surface using self-assembled monolayer (SAM) chemistry. The processes of adsorption and desorption of serum albumins onto the monolayer surfaces was monitored in real-time using surface plasmon resonance (SPR). Alkyl-terminated SAMs all showed a strong adsorption of bovine serum albumin which was largely independent of alkyl chain length, the ratio of mixed C4/C18 SAMs or the solution pH/ionic strength. The adsorption of human serum albumin to carboxylic and amine terminated SAMs was shown to be predominantly via non-electrostatic interactions (hydrophobic or hydrogen bonding). However, sulphonic acid terminated SAMs showed almost exclusively electrostatic interactions with human serum albumin. This preliminary work using self-assembled monolayer chemistry confirms the usefulness of well characterised SAMs surfaces for investigating protein adsorption and desorption onto/from model chromatography surfaces and gives some guidance for selecting appropriate functionalities to develop better surfaces for chromatography and electrophoresis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Animals
  • Cattle
  • Chromatography / instrumentation*
  • Humans
  • Hydrogen-Ion Concentration
  • Models, Chemical
  • Osmolar Concentration
  • Protein Binding
  • Serum Albumin / chemistry*
  • Serum Albumin / metabolism*
  • Sulfhydryl Compounds / chemistry
  • Sulfhydryl Compounds / metabolism
  • Surface Plasmon Resonance

Substances

  • Serum Albumin
  • Sulfhydryl Compounds