Mentors

Ren Sun, Ph.D. (Primary)
H. Tom Soh, Ph.D. (Secondary; SOMI Adjunct - UCSB)

Research Interests:

My research centers on the directed evolution of proteins in order to engineer binding reagents for detection and inhibition. To do this, we use mRNA display to select novel ligands from a scaffolded, single-domain, combinatorial library based on the immunoglobulin-like 10FnIII domain of human fibronectin. mRNA display is a totally in vitro selection technique that enables the monovalent and covalent linkage of protein and mRNA via the drug puromycin. This method enables us to use very high complexity combinatorial protein libraries of > 1 trillion unique sequences. Small (~10 kDa), stable, disulfide-free fibronectins evolved to high affinity for biomarker targets may prove to be ideal substrates for tumor imaging. Ultimately, by improving the throughput of mRNA display, our goal is to generate a standard set of ligands to cell-surface cancer markers, imaging of which may improve diagnosis and better predict outcome.

Olson CA, Liao HI, Sun R, and Roberts RW. (2008) mRNA display selection of a highaffinity, modification-specific, phospho-IkappaBalpha-binding fibronectin. ACS Chem. Biol. 3, 480-485.

Liao HI*, Olson CA*, Hwang S, Deng H, Wong E, Baric RS, Roberts RW, Sun R. (2009) mRNA display design of fibronectin-based intrabodies that detect and inhibit severe acute respiratory syndrome coronavirus nucleocapsid protein. J. Biol. Chem. 284, 17512-17520.

Roberts RW and Szostak JW. (1997) RNA-peptide fusions for the in vitro selection of peptides and proteins. PNAS. 94, 12297.