Geoffrey Chang

Who is Geoffrey Chang?

Geoffrey Chang is a professor at the University of California, San Diego's Skaggs School of Pharmacy and Pharmaceutical Sciences and Department of Pharmacology, School of Medicine. His laboratory focuses on the structural biology of integral membrane proteins, particularly exploring X-ray crystallography techniques for solving the tertiary structures of membrane proteins that are notoriously resistant to crystallization. The laboratory has specialized in structures of multidrug resistance transporter proteins in bacteria. In 2001, while a faculty member of The Scripps Research Institute, Chang was awarded a Beckman Foundation Young Investigator Award, designed to support researchers early in their academic careers, for his work on the structural biology of multidrug resistance.

Chang and coauthors published papers on the structures of two multidrug resistance transporters, known as EmrE, MsbA, and NorM between 2001 and 2010. Although the initial structures were widely considered puzzling in the field due to their unexpected placement of their ATP binding sites in the assembled dimer, the publication of an additional structure in the same protein family indicated that the Chang structures were unlikely to represent the biologically active conformation of the molecules. Chang and coauthors issued retractions of their structural papers on EmrE, MsbA and NorM, citing an error in an internal software utility as the source of the data misinterpretation that led to the appearance of wrongly assembled dimers. The application of a popular protein structure validation tool to one of the retracted MsbA structures results in scores that indicate severe errors in this structure.