Purification of an elastin-like fusion protein by microfiltration.

Journal Article (Journal Article)

This article describes a simple and potentially scalable microfiltration method for purification of recombinant proteins. This method is based on the fact that when an elastin-like polypeptide (ELP) is fused to a target protein, the inverse phase transition behavior of the ELP tag is imparted to the fusion protein. Triggering the phase transition of a solution of the ELP fusion protein by an increase in temperature, or isothermally by an increase in salt concentration, results in the formation of micron-sized aggregates of the ELP fusion protein. In this article, it is shown that these aggregates are efficiently retained by a microfiltration membrane, while contaminating E. coli proteins passed through the membrane upon washing. Upon reversing the phase transition by flow of Milli-Q water, soluble, pure, and functionally active protein is eluted from the membrane. Proof-of principle of this approach was demonstrated by purifying a fusion of thioredoxin with ELP (Trx-ELP) with greater than 95% recovery of protein and with greater than 95% purity (as estimated from SDS-PAGE gels). The simplicity of this method is demonstrated for laboratory scale purification by purifying Trx-ELP from cell lysate using a syringe and a disposable microfiltration cartridge. The potential scalability of this purification as an automated, continuous industrial-scale process is also demonstrated using a continuous stirred cell equipped with a microfiltration membrane.

Full Text

Duke Authors

Cited Authors

  • Ge, X; Trabbic-Carlson, K; Chilkoti, A; Filipe, CDM

Published Date

  • October 2006

Published In

Volume / Issue

  • 95 / 3

Start / End Page

  • 424 - 432

PubMed ID

  • 16767781

Electronic International Standard Serial Number (EISSN)

  • 1097-0290

International Standard Serial Number (ISSN)

  • 0006-3592

Digital Object Identifier (DOI)

  • 10.1002/bit.21046


  • eng