Abstract

Here we perform phage-assisted continuous evolution (PACE) of TEV protease, which canonically cleaves ENLYFQS, to cleave a very different target sequence, HPLVGHM, that is present in human IL-23. A protease emerging from ∼2500 generations of PACE contains 20 non-silent mutations, cleaves human IL-23 at the target peptide bond, and when pre-mixed with IL-23 in primary cultures of murine splenocytes inhibits IL-23-mediated immune signaling. We characterize the substrate specificity of this evolved enzyme, revealing shifted and broadened specificity changes at the six positions in which the target amino acid sequence differed. Mutational dissection and additional protease specificity profiling reveal the molecular basis of some of these changes. This work establishes the capability of changing the substrate specificity of a protease at many positions in a practical time scale and provides a foundation for the development of custom proteases that catalytically alter or destroy target proteins for biotechnological and therapeutic applications.

Details

Title
Phage-assisted continuous evolution of proteases with altered substrate specificity
Author
Packer, Michael S 1 ; Rees, Holly A 2 ; Liu, David R 3 

 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Graduate Program in Biophysics Program, Harvard University, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA 
 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA 
 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA 
Pages
1-11
Publication year
2017
Publication date
Oct 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1953962648
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.