Joshua Pixley earned his undergraduate degree from the University of Chicago in an unusual triple major—molecular engineering, chemistry, and biochemistry—just in time to help solve one of molecular biology's most stubborn problems: how to target a disease protein without accidentally harming its near-identical healthy twin.

The challenge seems almost cruel in its specificity. The RAS family of proteins, implicated in more than 90% of pancreatic cancers, includes members like HRAS and KRAS that share 94% of the same genetic sequence. That remaining 6% difference carries vastly different clinical weight: KRAS drives pancreatic cancer, while HRAS contributes to bladder and head-and-neck cancers. Yet for decades, researchers have struggled to develop drugs that could selectively attack one without disabling the other. The traditional solution meant months of exhausting laboratory work just to identify a single molecular binder capable of making that distinction.

Now, Pixley and his colleagues in Professor Bryan Dickinson's lab at UChicago have unveiled PANCS-spec-Binders, a breakthrough platform that compresses that timeline from months to weeks. Published in PNAS, the work demonstrates a fundamentally faster way to engineer ultra-specific protein-interacting partners—binders that can zero in on a single target while entirely ignoring its near-identical cousins.

The platform harnesses a synthetic library containing more than 10 billion potential binding partners. Rather than testing them one by one, the system uses active bacteriophage replication to screen the enormous pool within days. Validation happens through engineered bacterial strains that literally glow when a successful molecular interaction occurs, completely bypassing the traditional protein purification bottlenecks that have long slowed discovery. The acceleration is striking: Pixley notes that researchers can move "from an idea for a protein that you'd like to find an interacting partner for all the way through something that is completely workable and ready to employ within just a couple of weeks."

A concurrent study published in the Journal of the American Chemical Society proved this speed in real time. Collaborating with a UChicago cancer laboratory, the team went from receiving uncharacterized protein IDs to delivering fully functional binders optimized for mini-protein degraders in just 26 days—a workflow that traditionally would have consumed six to twelve months.

The development revealed something unexpected about protein biology itself. When the team investigated why their newly discovered binder displayed such flawless selectivity for HRAS over KRAS, the answer eluded traditional structural analysis. The secret, it turned out, lay in a single amino acid within a highly flexible, frequently overlooked region of the target protein—a finding that caught even the researchers by surprise. That one spot, Pixley explains, "was the key driver of the selectivity which we were seeing."

The discovery exposes a gap in how scientists have long studied protein structure, overlooking dynamic regions in favor of rigid, well-defined domains. It's a reminder that biological solutions often hide in plain sight, waiting for the right technology and persistence to reveal them. For researchers targeting diseases where protein dysregulation is the root cause—cancers, neurodegenerative diseases—this platform opens new possibilities for precision intervention where selectivity was once impossible.