Abstract

A 66kD membrane protein from the surface of Erysipelothrix rhusiopathiae has been determined to play an important role in eliciting an immunoprotective response in immunized animals. ELISAs using this purified 66kD surface protein indicate that it has potential as a capture antigen. The current process of isolating the 66kD protein is tedious, time consuming and does not provide good yields. Molecular cloning and expression of specific gene sequences often provide a convenient means of producing an appreciable amount of desired protein product. In this study, several ATCC reference strains of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum were analyzed using the polymerase chain reaction to demonstrate the presence or absence of the gene sequence of the 66kD membrane protein. Subsequently, the 66kD gene sequence of the Navy isolate of Erysipelothrix rhusiopathiae was cloned and expressed in the PurePro Caulobacter expression system. The expressed protein product was then characterized and compared to the native protein product using N-terminal amino acid sequencing and protein digestion using various proteolytic enzymes. Cloning and expression of the 66kD membrane protein of Erysipelothrix rhusiopathiae provides a relatively quick and easy method of producing enough protein product for subsequent applications