SECONDARY APPOINTMENT(S)/ INSTITUTE(S)/ CENTER(S):
Penn State Hershey Cancer Institute
M,S. Cornell University, 1981
Ph.D. Cornell University, 1984
Postdoctoral Associate, Brandeis University, 1984-1988
Research in Dr. Sung’s laboratory is concerned with understanding intra-protein and protein-ligand interactions, using modeling and computational methods. With solvent effects, these interactions determine protein structures and protein-ligand binding structures. Despite many decades of research, these interactions have not been fully understood and structure prediction involving proteins remains a largely unsolved problem. Protein structures are currently determined experimentally by X-ray crystallography or NMR spectroscopy. However, small peptide folding simulations have shown good agreement with experimental observations. Calculated conformational changes upon binding have greatly improved docking results. Homology modeling based on known structures has shown successes in a number of studies of protein interaction with other molecules. It is especially important for studying proteins difficult to crystallize, such as trans-membrane proteins.
The study of protein-ligand interactions is directly applicable to drug discovery. With experimentally determined structures or homology models, molecules of interest in drug discovery are docked into the binding site of these proteins to estimate their binding strengths and to predict binding structures. Automated docking of a large number of molecules is performed to virtually screen compound databases, to generate a list of molecules with high probability to be active in inhibiting protein functions. These compounds will then be tested experimentally to verify their activity. Calculated docking structures will guide the design and synthesis of more active compounds in the lead optimization process. De Novo drug design is performed using the binding site structures. By comparing the structures of active compounds, a quantitative structure-activity relationship will be established and a pharmacophore model will be constructed, which contains essential structural components for activity. Currently, research in this lab is applied to several target proteins, including Mcl, LC3, S1P, SK, ROCK, AKT, ANP, SIRT3, HDAC, and Pin1, in the development of new medicines for the prevention and treatment of cancer and other diseases.