Unit

UNIT 16.5 Expression and Purification of lacZ and trpE Fusion Proteins

  1. Timothy Hoey

Published Online: 1 MAY 2001

DOI: 10.1002/0471142727.mb1605s28

Current Protocols in Molecular Biology

Current Protocols in Molecular Biology

How to Cite

Hoey, T. 2001. Expression and Purification of lacZ and trpE Fusion Proteins. Current Protocols in Molecular Biology. 28:I:16.5:16.5.1–16.5.6.

Author Information

  1. University of California, Berkeley, California

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: OCT 1994

Abstract

Fusion proteins are commonly used as a source of antigen for producing antibodies and in many cases can be useful for biochemical analyses. This unit describes two widely used expression systems for producing large amounts of proteins in E. coli. One system expresses lacZ fusions using the pUR series of vectors and the other expresses trpE fusions using the pATH vectors. The gene of interest is first subcloned into either a pUR or pATH vector in the correct reading frame. The correct transformant is selected, grown, and then induced with either IPTG or IAA. Sonication of cells in the presence of protease inhibitors is used to prepare extracts containing both types of fusion proteins, as well as other types of proteins overexpressed in E. coli. The extracts are checked for the presence of fusion protein on an SDS-polyacrylamide gel.