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

Area of Science:

• Surface Chemistry
• Biomaterials Science
• Chromatography

Background:

• Chromatographic stationary phases are crucial for separating biomolecules.
• Understanding protein adsorption onto surfaces is key to optimizing chromatographic performance.
• Self-assembled monolayers (SAMs) offer a versatile platform for creating well-defined model surfaces.

Purpose of the Study:

• To develop model surfaces mimicking chromatographic stationary phases using SAM chemistry.
• To investigate the adsorption and desorption behavior of serum albumins on various SAM surfaces.
• To guide the selection of surface functionalities for enhanced chromatography and electrophoresis.

Main Methods:

• Fabrication of model surfaces by immobilizing n-alkylthiols and functionalized thioalkanes onto silver-coated glass using SAM chemistry.
• Real-time monitoring of protein adsorption and desorption using surface plasmon resonance (SPR).
• Systematic variation of surface chemistry (alkyl chain length, terminal groups) and solution conditions (pH, ionic strength).

Main Results:

• Alkyl-terminated SAMs exhibited strong bovine serum albumin adsorption, independent of chain length or solution conditions.
• Human serum albumin adsorption to carboxylic and amine-terminated SAMs was primarily non-electrostatic (hydrophobic/hydrogen bonding).
• Sulphonic acid-terminated SAMs showed predominantly electrostatic interactions with human serum albumin.

Conclusions:

• Well-characterized SAM surfaces are valuable for studying protein adsorption and desorption in chromatography.
• Surface functionalization significantly influences protein-surface interactions.
• This study provides insights for designing improved stationary phases for chromatography and electrophoresis.