Analysis of Viral Antigens Using Biosensor Technology

The different types of epitopes found in viral antigens are described. The BIAcore has been used successfully to map the location of epitopes in viral antigens and several examples of such studies are presented. Knowledge of the affinity of viral antibodies is important for understanding the molecular basis of viral antigenicity and the mechanism of infectivity neutralization by antibodies. The use of the BIAcore for measuring binding constants of viral antibodies is described. Affinity constants of antibodies binding to virus particles are easily obtained using sensor chips on which the virus is immobilized by a first layer of antibodies. Affinity constants obtained with the BIAcore agree closely with values obtained by several other methods of affinity determination. By comparing the binding properties of neutralizing and nonneutralizing viral antibodies with the BIAcore, it should be possible to establish whether there is a relationship between affinity and neutralizing capacity of antibodies. By immobilizing synthetic peptides corresponding to viral epitopes on sensor chips, the BIAcore can also be used to quantitate antibody to specific epitopes present in polyclonal antiserum.