Alvan C. HenggeAlvan C. Hengge

Professor
Organic Chemistry
B.S., 1974, University of Cincinnati
Ph.D., 1987, University of Cincinnati
Postdoctoral, 1987-90, University of Wisconsin
Asst. Scientist, 91-96, Institute for Enzyme Research
435.797.3442 hengge@cc.usu.edu
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Research in my laboratory straddles the fields of biochemistry and organic chemistry. We are interested in characterizing the mechanistic details of chemical reactions, especially those of biological interest. We also study enzymatic catalysis, with the goal of understanding the origins of the tremendous catalytic power of enzymes. Students in my research group learn a wide variety of skills than span the fields of chemistry and biochemistry.

Ongoing projects are examining the chemistry of phosphate esters and sulfate esters. These compounds have great importance in biological systems, where their hydrolysis and their formation are catalyzed with remarkable efficiency by enzymes at rates millions of times (or more) faster than analogous uncatalyzed reactions. Our research seeks to understand how enzymes accomplish this remarkable chemistry. Phosphoryl transfer. Protein kinases and phosphatases have been called the Yin and Yang of signaling in the cell. In both plants and animals, and from humans to bacteria, protein
phosphorylation plays a central role in regulating cellular processes. The enzymes in this family have essential roles in regulation of metabolic processes and in disease. We are studying the mechanisms of catalysis of several of theses enzymes. Some phosphatases utilize a dinuclear metal center in catalysis, while others do not utilize metal ions. Of particular interest is whether these disparate phosphatase families utilize similar or different mechanisms to cleave their normally very stable phosphate ester substrates.

Sulfuryl transfer.

Sulfation has a crucial biological role in detoxification. In addition, sulfate monesters are found among all the classes of natural products, including nucleotides, peptides and proteins, polysaccharides, steroids, and lipids.

Sulfate ester chemistry has historically been a relatively neglected area. A great deal remains to be discovered about these compounds, and the enzymes that process them in biological systems. We are studying the uncatalyzed reactions of sulfate esters in solution, as well as several enzymatic sulfuryl transfer reactions.


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Selected Publications

Y. Liu, B. A. Gregersen, A. C. Hengge and D. M. York.  "Transesterification Thio Effects of Phosphate Diesters: Free Energy Barriers and Kinetic and Equilibrium Isotope Effects from Density-Functional Theory"  Biochemistry;2006;  45(33);  10043-10053.

K. Sorensen-Stowell and A. C. Hengge .  "Thermodynamic Origin of the Increased Rate of Hydrolysis of Phosphate and Phosphorothioate Esters in DMSO/Water Mixtures."  J. Org. Chem.; 2006;  71(19);  7180-7184.

R, H. Hoff, P, G. Czyryca, M, Sun, T, S. Leyh, and A, C. Hengge.  "The Transition State of the Sulfuryl Transfer Reaction of Estrogen Sulfotransferase"  Journal of Biological Chemistry, 2006, 281, 30645-30649.

W. W. Cleland and A. C. Hengge.  "Enzymatic Mechanisms of Phosphate and Sulfate Transfer"  Chemical Reviews;  2006;  106(8);  3252-3278

J. Purcell and A. C. Hengge "The Thermodynamics of Phosphate versus Phosphorothioate Ester Hydrolysis" Journal of Organic Chemistry, 2005, 70 (21): 8437-8442.