Orientation Specific Positioning of Organophosphorus Hydrolase on Solid Interfaces for Biosensor Applications

Protein immobilization on solid interfaces is a crucial aspect of their successful application in technologies such as biosensing, purification, separation, decontamination, etc. Although immobilization can improve the long-term and operational stability of proteins, this is often at the cost of significant losses in the catalytic activity of the tethered enzyme. Covalent attachment methods take advantage of reactive groups on the amino acid side chains. The distribution of the solvent exposed side chains on an enzyme’s molecular surface often results in an ensemble of orientations when the protein is immobilized on a surface or in a matrix through these side chain linkages. Depending on the attachment mechanism and resulting orientation, access to and from the active site could be restricted. This study describes a methodology for the design and implementation of an orientation specific attachment of an enzyme to a surface plasmon resonance sensor surface. The enzyme, organophosphorus hydrolase, was stru...