Epitope-Cavities Generated by Molecularly Imprinted Films Measure the Coincident Response to Anthrax Protective Antigen and Its Segments

摘要

A molecularly imprinted film was fabricated, in the presence of epitope-peptides, onto a quartz crystal microbalance (QCM) chip. These five peptides are known linear or conformational epitopes of the anthrax protective antigen PA_(83). Imprinting resulted in an epitope-cavity with affinity for the corresponding template. With the use of a basic monomer, the binding-effect was further enhanced increasing the affinity to nanomolar levels. The affinities of the peptide to their corresponding molecularly induced polymers (MIPs) were more closely related to the molecular weight of the analyte than to the number of residues. All epitope-cavities differentiated their epitope region on the protective antigen PA_(83) as well as the corresponding furin cleavage fragments PA_(63) and PA_(20). The QCM chip differential response to the protective antigen fragment was observed in the picomolar range, thus demonstrating a method to manipulate protein on the surface with defined orientation.