How Proteins Get Where They’re Supposed to Go


Proteins are only synthesized at specialized cellular locations, but are destined for delivery to all corners of the cell—and beyond. A key step in this delivery process is the efficient transport, or translocation, of the newly synthesized proteins across cell membranes. Protein translocation involves a delicate balance of processes that range from atomic-level interactions to macromolecule-scale rearrangements.

On Wednesday, May 11, at 8 p.m. in Beckman Auditorium, Caltech professor of chemistry Thomas Miller will explain how his group is simulating the protein translocation process and predicting ways to control the targeting and delivery of proteins for therapeutic and biotechnological applications. Admission is free.

What do you do?

I am a theoretical chemist. We develop mathematical models and computational algorithms for the simulation and understanding of chemical processes. We use this approach to study a range of problems, including electrolyte performance and degradation in batteries, solar energy conversion, and the cellular targeting and synthesis of proteins. An important aspect of this challenge is that many systems exhibit dynamics that couple vastly different timescales and lengthscales. A primary goal of our research is thus to develop new computational strategies to accurately and efficiently simulate complex molecular systems.

Why is this important?

Many of the urgent problems facing our society—including the generation and storage of renewable energy, the development of improved medicines, and the design of new materials—are fundamentally related to molecular processes (i.e., chemistry). Theoretical chemistry provides the tools to understand the underlying molecular behavior, to help interpret experimental measurements, and to predict new properties and phenomena. Just like computer simulations have dramatically impacted the fields of weather and climate prediction, traffic flow, and demographics—so too have they become central to the way in which we understand and study chemical problems. Theoretical chemistry is the field that makes this possible.

How did you get into this line of work?

I have always enjoyed chemistry, physics, and math, as well as the challenge of getting to the bottom of complicated problems. So the thing that “seduced” me into becoming a theoretical chemist was the realization that those interests coincided in the description of molecules. A major turning point in my career came in my freshman year, when I learned the way in which the Schrödinger Equation provided a simple, clear, and essentially exact mathematical description of chemical bonding. The idea that all of chemistry rests upon this equation from physics and the mathematical challenge of solving it was simply too intriguing to pass up. I immediately began participating in undergraduate research in a theoretical chemistry lab, and I have since enjoyed the myriad directions in which this pursuit has led.

Written by Lori Dajose