ABSTRACT
Antibodies (Abs) have long been used for studying protein structure in solution because of their specificity in recognition of structure and conformation [1]. Abs recognize the antigenic determinant (epitope) that has structural complementarity to the Ab-combining site (paratope). Epitopes have been classified into two types: “linear or segmental” and “conformational or topographic” [2-6]. Linear epitopes are determined by their linear amino acid sequences, while conformational epitopes are related to the three-dimensional protein structure and are considered to be an assemblage of several amino acid segments. Abs prepared by immunization of animals with native proteins seem to largely recognize conformational epitopes and sometimes fail to react with denatured proteins or peptides [2]. These Abs, therefore, cannot be used for detection of proteins by Western blotting analysis after SDS-PAGE. On the other hand, Abs prepared by immunization with synthetic peptides are able to bind to both native and denatured proteins, and can be used for isolating and characterizing gene products.
