REVERSIBLE ORIENTED SURFACE IMMOBILIZATION OF FUNCTIONAL PROTEINS ON OXIDE SURFACES

Reversible and oriented immobilization of proteins in a functional act ive form on solid surfaces is a prerequisite for the investigation of molecular interactions by surface-sensitive techniques. We demonstrate a method generally applicable for the attachment of proteins to oxide surfaces. A nitrilotriacetic acid group sewing as a chelator for tran sition metal ions was covalently bound to the surface via silane chemi stry. Reversible binding of the green fluorescent protein, modified wi th a hexahistidine extension, was monitored in situ using total intern al reflection fluorescence. The association constant and kinetic param eters of the binding process were determined, The reversible, directed immobilization of proteins on surfaces as described here opens new wa ys for structural investigation of proteins and receptor-ligand intera ctions.