Monomolecular Organization of a Photodynamic Protein System Through SpecificSurface Recognition of Streptavidin to Biotinylated LB Films

摘要

This paper focuses on a novel methodology for the two-dimensional ordering of aphotodynamic protein system using the Langmuir-Blodgett (LB) technique. The specific versus non-specific surface recognition of biotin or biotinylated LB monolayers by streptavidin and avidin conjugated phycoerthrin was investigated. Both avidin and streptavidin conjugates, when injected under the biotinylated monolayer, were found to preferentially adsorb to the biotin while at the air-water interface. Pressure-area isotherms displayed a biotin-streptavidin/avidin complex dependent increase in surface pressure at expanded areas indicating protein adsorption. Fluorescence measurements of transferred films confirmed the binding of phycoerythrin to the monolayers and provided evidence that the avidin conjugated system may bind by both specific and non-specific mechanisms, while the streptavidin systems bind through only a specific mechanism. The extension of this methodology to any biotin or avidin/streptavidin derivatized protein system is expected to lead to the fabrication of ultrathin, ordered, protein molecular assemblies with potential bioelectronic, optical and protein structure research applications.