ISBE 2019

Rational design of light-responsive elastin-like polypeptides, using non-standard amino acids

Bar Israeli Sigal Gelkop Miriam Amiram
Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel

Photosensitive bioactive molecules have great potential in basic science and medical applications. Using light as a trigger for remote control allows spatio-temporal activation of biomolecules, without invasive procedures. Here we present rationally designed Elastin-like polypeptide (ELP), that phase-transition in response to light irradiation. ELPs are a family of stimulus-responsive protein polymers that comprises artificial repetitive polypeptides composed of a VPGXG repeat, where X can be any amino acid except proline [1]. Therefore, the X-position is also permissive to non-standard amino acid (nsAA) incorporation [2]. Notably, ELPs undergo a reversible soluble-to-insoluble phase transition at their lower critical transition temperature (Tt), which depends on the ELP composition [1]. In this work, we aim to generate light-responsive ELPs by incorporation of azobenzene-containing non-standard amino acid (nsAA) [3] in the X-position of the ELP sequence. Azobenzenes are a class of molecules known to undergo reversible light-based isomerization from trans to cis, which also impacts the polarity of the molecule. To incorporate multiple instances of azobenzene-nsAAs we utilized an improved orthogonal translation system (OTS) and genomically recoded organisms. We show that multi-site-specific incorporation of nsAAs into a polypeptide can facilitate the production of complex and precise biopolymers using a relatively simple methodology. Ultimately, the engineering of light-responsive phase transition in ELPs, using site-specific azobenzene incorporation, can be used as a basis for engineering an entire family of novel light-responsive biomaterials.

References

  1. R. MacEwan, A. Chilkoti, Biopolymers 2010, 94, 60-77.
  2. Amiram, A. D. Haimovich, C. Fan, Y. S. Wang, H. R. Aerni, I. Ntai, D. W. Moonan, N. J. Ma, A. J. Rovner, S. H. Hong, N. L. Kelleher, A. L. Goodman, M. C. Jewett, D. Soll, J. Rinehart, F. J. Isaacs, Nat Biotechnol 2015, 33, 1272-1279.
  3. Bose, D. Groff, J. Xie, E. Brustad, P. G. Schultz, J Am Chem Soc 2006, 128, 388-389.









Powered by Eventact EMS