title: Protein interactions with model chromatographic stationary phases constructed using self-assembled monolayers.
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.
authors.affiliation: School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK. david.barrett@nottingham.ac.uk
authors.forename: David A
authors.initials: DA
authors.lastname: Barrett
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Power
authors.forename: Maruf A
authors.initials: MA
authors.lastname: Hussain
authors.forename: Ian D
authors.initials: ID
authors.lastname: Pitfield
authors.forename: P Nicholas
authors.initials: PN
authors.lastname: Shaw
authors.forename: Martyn C
authors.initials: MC
authors.lastname: Davies
mesh_terms: D000478:Alkylation; D000818:Animals; D002417:Cattle; D002845:Chromatography / Q000295:instrumentation*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D009994:Osmolar Concentration; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: D012709:Serum Albumin; D013438:Sulfhydryl Compounds