University of California, Riverside

Department of Chemistry




Chia-en Chang
Professor of Chemistry Department Vice-Chair & Bioinformatics


University of Maryland, College Park - Ph.D. (2003)
University of Maryland Biotechnology - Research Associate (2003-2004)
University of California, San Diego - Postdoc. (2005-2007)

Office: 420 Chemical Sciences
Phone O/L: (951) 827-7263
Research Area: Computational Chemistry, Chemical Biology, Physical Chemistry
Group Site


The central goal of our work is to understand the fundamental mechanism of biomolecular recognition and binding kinetics using theory and classical mechanical models. Our research involves the development and application of computational methods and theoretical models to address medically and chemically important problems. These methods are of practical importance in studying biomolecular function, and in the design of new molecules that bind strongly to their receptors. Systems of particular interest include existing or potential drug targets, cell signaling complexes and chemical host-guest systems.

Multiscale modeling of biomolecular systems: Computer modeling is becoming increasingly valuable for understanding protein function and ligand-receptor interactions. Atomistic molecular dynamics, coarse-grained Brownian dynamics and continuum simulations are combined to study detailed molecular interactions, large scale protein motions, bio-molecular dynamics, and complex biochemical network. We continue developing new methods, as well as applying them to various problems, e.g. binding pathways of ligands to HIV-1 protease, assembly and motions of acetylcholinesterase tetramer, and functions of signaling and multifunctional protein complexes.

Kinetics of binding: The association of two free molecules to form a complex is one of the most important processes in chemical and biological systems. The binding affinity, or the standard free energy change of binding, is simply an alternative way of expressing its equilibrium constant K(sub-eq)=exp(-Go/RT), which in turn is the ratio of the rate-constants for association k(sub-on) and dissociation k(sub-off). It has been shown experimentally that different molecules that bind to the same chemical receptor may have similar binding free energies (G), but very different binding kinetics (kon, koff). It is unclear why their kinetic features are very different. Therefore, our lab studies not only equilibrium properties, such as the free energy of binding, but also the kinetics of binding. Since basic research, e.g. computational methodology and theories, is needed in this field, we start from tractable simplified models, and then move to more complicated chemical systems and biomedically relevant systems.

Computer-aided ligand/receptor design and discovery: In drug design and discovery, finding a small molecule that maximizes binding free energy is very important and is an interesting challenge. A thorough understanding of driving forces, binding penalties, and conformational changes induced by ligand binding, should enable more accurate prediction of binding affinities. Our lab assembles state of the art methods, e.g. docking and scoring, and applies our work described above to improve the ligand-design work.


Selected Publications


More Information 

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Department of Chemistry
Chemical Sciences
501 Big Springs Road

Tel: (951) 827-3789 (Chair's Assistant)
Fax: (951) 827-2435 (confidential)