Simplified protein purification using engineered self-cleaving affinity tags

The biological revolution, spurred on by the completion of the human genome project, will increase the demand for inexpensive and reliable methods for protein expression and purification. Over the past 20 years, several technologies have been developed where target proteins or expression systems are manipulated at the genetic level to increase productivity. The use of genetically-fused affinity tags has been particularly successful, and this technique has become ubiquitous in research. However, the high cost of this approach, along with some regulatory issues, have prevented it from becoming more widely adopted at large scale. Recently, self-cleaving protein elements have been developed that can effectively make affinity tags self-cleaving, allowing the release of the product directly from the affinity column under extremely mild conditions. The low cost of this approach, combined with the power of an affinity separation, promise to make this an exciting new purification technology for future research and manufacturing applications. (C) 2003 Society of Chemical Industry.