Date of Award

2009

Degree Type

Thesis

Degree Name

Master of Science

Program

Biology

Supervisor

Dr. Rima Menassa

Abstract

Traditional protein purification methods are costly at the industrial scale. As therapeutic peptides demonstrate their potency against human disease, a strong impetus towards commercialized production emphasizes the development of novel purification methods. A two-component system was developed in tobacco BY-2 cells that used an elastin-like polypeptide tag and a terminally-cleaving small molecule-dependent intein to purify a green fluorescent protein (GFP) fusion protein and remove the purification tag from it. The small molecule-dependent intein, originally developed in yeast, appeared to splice illegitimately in tobacco BY-2 cells, yielding non-functional GFP, and exhibiting significant uninduced splicing. Conversely, once the intein was modified to cleave either at the N- or C-terminus, cleavage only occurred in a controlled manner in the C-terminus fusion protein through pH reduction. Inverse transition cycling of the elastin-like polypeptide (ELP) purification tag concentrated rather than purified the target protein, suggesting an alternative economical purification tag is required for cell extract purification.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.