Academic Education:

B.S., University of Kentucky
Ph.D., University of California at Berkeley


Appointments:

NSF Fellow, University of California, Berkeley (1970-1975)

NIH Postdoctoral Fellow, Cornell University Medical College, New York (1975-1978)

Instructor, Cornell University Medical College, New York (1978-1979)

Assistant Professor, Cornell University Medical College, New York (1979-1983)

Assistant Professor, Northeastern University, Boston (1983-1988)

Associate Professor, Northeastern University, Boston (1988-1999)

Professor, Northeastern University, Boston (1999-present)

Interim Chair of Biology, Northeastern University, Boston (2000-2003)

Chair of Biology, Northeastern University, Boston (2003-2006)

Vice Provost for Undergraduate Education, Northeastern University, Boston (2006-2008)

Vice Provost for Undergraduate and Cooperative Education, Northeastern University, Boston (2008-2011)

Vice Provost for Honors and First-Year Programs, Northeastern University, Boston (2011-present)

Other Professional Activities:

Editorial Board: Journal of Biological Chemistry (1988-1993, 1995-2000, 2004-2009); Protein Expression and Purification (1990-2007; founding board member)

Member, Educational Affairs Committee of the American Society of Biochemists and Molecular Biologists (1986-1989)

Member, NIH Special Study Section C3 (June, 1985); NIH Medical Biochemistry Study Section (7/1/93-6/30/97); NIH Special Emphasis Panel (October, 2000); NIH Special Emphasis Panel, April, 2002; NIH Special Emphasis Panel (March, 2003)


Research Interests:

My lab studies how protein structures have evolved to catalyze unique enzymatic activities, and to participate in a diverse set of intracellular communications. Our recent studies have been focused on human detoxification of ammonia and its control mechanisms. Carbamoyl phosphate synthetase (CPS), which catalyzes the entry and regulated step of the urea cycle, is known to be the primary site of ammonia detoxification. These studies have utilized structural, biochemical, molecular and bioinformatics techniques to define the structure and function of human CPS and to relate these parameters to those of potential evolutionary relatives. We have also reverse engineered various CPSs by creating site-directed mutants, truncated constructions and chimeras. Additionally, studies have been aimed at elucidation of the intramitochondrial environment for CPS and its effect on the enzyme's structure and function. Applications of these studies include developing treatments for hepatitis and other disorders in which liver function is temporarily or permanently altered. Please note that I am not accepting new lab members while I am serving in the Office of the Provost.

Teaching Activities:

Currently I have oversight of Northeastern's honors and first-year curriculum.  I have taught at the University of California at Berkeley, Cornell University Medical College and Northeastern University in the area of biochemistry, and have designed lecture and lab courses for both undergraduate and graduate students.

Selected Publications:

Hart, E.J., and Powers-Lee, S.G., “Role of Cys-1327 and Cys-1337 in Redox Sensitivity and Allosteric Monitoring in Human Carbamoyl Phosphate Synthetase” J. Biol. Chem. 284, 5977-5985 (2009).

Ahuja, V., and Powers-Lee, S.G., "Human Carbamoyl Phosphate Synthetase: Insight into N-Acetylglutamate Interaction and the Functional Effects of a Common Single Nucleotide Polymorphism" Journal of Inherited Metabolic Disease 31, 481-491 (2008).

Hart, E. J., and Powers-Lee, S.G., "Mutation analysis of carbamoyl phosphate synthetase: Does the structurally conserved glutamine amidotransferase triad act as a functional dyad?" Protein Science 17, 1120-1128 (2008).

Kothe, M., Purcarea, C., Guy, H. I., Evans, D. R., and Powers-Lee, S. G., "Direct Demonstration of Carbamoyl Phosphate Formation on the C-terminal Domain of Carbamoyl Phosphate Synthetase," Protein Science, 14, 37-44 (2005).

Kothe, M., and Powers-Lee, S.G., "Nucleotide Recognition in the ATP-Grasp Protein Carbamoyl Phosphate Synthetase," Protein Science, 13, 466-475 (2004).

Saeed-Kothe, A., and Powers-Lee, S.G. "Gain of Glutamine Function in an Ammonia Specific Carbamoyl Phosphate Synthetase," J. Biol. Chem. 278, 26722-26726 (2003).

Eroglu, B., and Powers-Lee, S.G., "Unmasking a Functional Allosteric Domain in an Allosterically Nonresponsive Carbamoyl Phosphate Synthetase," J. Biol. Chem. 277, 45466-45472 (2002).

Eroglu, B., and Powers-Lee, S.G., "Mutational Analysis of ATP-Grasp Residues in the Two ATP Sites of Saccharomyces cerevisiae Carbamoyl Phosphate Synthetase," Archives Biochem. Biophys. 407, 1-9 (2002).

Saeed-Kothe, A., and Powers-Lee, S.G., "Specificity Determining Residues in Ammonia and Glutamine Dependent Carbamoyl-Phosphate Synthetases," J. Biol. Chem. 277, 7231-7238 (2002).

Complete List of Publications

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