An orthogonal fusion tag for efficient protein purification

Abstract

Protein fusion tags are important tools in research when robust methods for protein purifi cation and detection are required. In this chapter we present an effi cient method for stringent protein purifi cation. A small domain, denoted ABDz1, with affi nity for both human serum albumin and Protein A has been developed. The purifi cation tag is based on an albumin-binding domain from Streptococcal Protein G that was engineered to bind Protein A. The ABDz1-tag can be fused to any protein of choice and the purifi cation can be performed using standard laboratory equipment. In this chapter a method for purifi cation of ABDz1-tagged proteins using two successive affi nity purifi cation steps is described.