Biochemistry and Molecular Biology

Donald Spratt

Donald E. Spratt, Ph.D.

Assistant Professor of Chemistry and Biochemistry
Carl J. and Anna Carlson Endowed Chair
Clark University
Worcester, MA 01610-1477

Office: S226, Sackler Sciences Center
Phone: 508-793-7536
Email: dspratt@clarku.edu

Curriculum Vitae
Research Website


Education 

Research Associate, University of Western Ontario, 2011-2015
Postdoctoral Fellow, University Western Ontario, 2008-2011
Ph.D. University of Waterloo, 2008
B.Sc. Mount Allison University, 2003

Current Research and Teaching

The regulation of enzyme catalysis and protein function resulting from the specific interactions between two or more proteins plays an integral role in cell division and homeostasis. The development of various human diseases can occur when these protein-protein interactions are disrupted or modified. Understanding how these protein-protein interactions affect an enzyme’s ability to make or break bonds and its underlying mechanism is an important step in drug design/development.

Ubiquitylation involves the transfer of the small 76-residue protein ubiquitin between a series of enzymes (E1, E2, E3) until it labels the e-amino group of a lysine residue on a substrate protein. This pathway is involved in many different intracellular processes including protein turnover, cell cycle progression, signal transduction, DNA repair and transcriptional regulation. Our research program focuses on deciphering the unique mechanisms employed by members of the HECT (Homologous to E6AP Carboxyl Terminus) E3 ubiquitin ligase family. Working at the interface of physical biochemistry and chemical biology, our research team uses biochemical and biophysical techniques including NMR spectroscopy to understand how HECT E3 ubiquitin ligases attach ubiquitin or ubiquitin-like proteins to a substrate protein. Specifically, our group is focused on the following themes:

  1. Molecular basis for specificity in ubiquitin chain linkage by the HECT E3 ligases
  2. Mechanism and ubiquitin handling by the HECT E3 ligases
  3. Substrate recognition by the HECT E3 ligases

Our studies will help to clarify how HECT E3 ligases form multi-protein complexes to build ubiquitin chains and how the malfunction of these complexes cause cancer.

Selected Publications

Kumar, A., Aguirre, J.D., Condos, T.E.C., Martinez-Torres, R.J., Chaugule, V.K., Toth, R., Sundaramoorthy, R., Mercier, P., Knebel, A., Spratt, D.E., Barber, K.R., Shaw, G.S., and Walden, H. (2015) “Disruption of the autoinhibited state primes the E3 ligase parkin for activation and catalysis.” EMBO J. Aug 7. pii: e201592337.

Spratt, D.E., Walden, H., and Shaw, G.S. (2014) “RBR E3 ubiquitin ligases: new structures, new insights, new questions.” Biochem. J. 458, 421-437.

Chong, R.A., Wu, K., Spratt, D.E., Yang, Y., Lee, C., Nayak, J., Xu, M., Elkholi, R., Li, J., Brown, B.D., Chipuk, J.E., Chen, Z., Sanchez, R., Shaw, G.S., Huang, L., and Pan, Z.-Q. (2014) “Pivotal role for the ubiquitin Y59-E51 loop in lysine-48 polyubiquitination.” Proc. Natl. Acad. Sci. U.S.A.111, 8434-8439.

Kovacev, J., Wu, K., Spratt, D.E., Chong, R.A., Nayak, J., Shaw, G.S., and Pan, Z.-Q. (2014) “A snapshot at ubiquitin chain elongation: lysine 48-tetra-ubiquitin slows down ubiquitination.” J. Biol. Chem.289, 7068-7081.

Spratt, D.E., Martinez-Torres, R.J., Noh, Y.J., Mercier, P., Manczyk, N., Barber, K.R., Aguirre, J.D., Burchell, L., Purkiss, A., Walden, H., and Shaw, G.S. (2013) “A molecular explanation for the recessive nature of parkin-linked Parkinson’s disease.” Nat. Commun.4, 1983.

Spratt, D.E., Mercier, P., Shaw, G.S. “Structure of the HHARI catalytic domain shows glimpses of a HECT E3 ligase.” (2013) PLoS ONE 8, e74047.

Spratt, D.E., Wu, K., Kovacev, J., Pan, Z.-Q., and Shaw, G.S. (2012) “Selective recruitment of an E2~ubiquitin complex by an E3 ubiquitin ligase.” J. Biol. Chem. 287, 17374-17385.

Piazza, M., Futrega, K., Spratt, D.E., Dieckmann, T., and Guillemette, J.G. (2012) “Structure and dynamics of calmodulin (CaM) bound to nitric oxide synthase peptides: effects of a phosphomimetic calmodulin mutation.” Biochemistry 51, 3651-3661.

Spratt, D.E., and Shaw, G.S. (2011) “Association of the disordered C-terminus of CDC34 with a catalytically-bound ubiquitin.” J. Mol. Biol.407, 425-438.

Piazza, M., Duangkham, Y., Spratt, D.E., Dieckmann, T., and Guillemette, J.G. (2011) “Expression and purification of an isotopically labeled aggregation prone iNOS CaM binding protein for use in NMR studies.” J. Label. Compd. Radiopharm. 54, 657-663.

Spratt, D.E., Duangkham, Y., Taiakina, V., and Guillemette, J.G. (2011) “Mapping the binding and calmodulin-dependent activation of nitric oxide synthase isozymes.” The Open Nitric Oxide Journal 3, 16-24.

Marlatt, N.M., Spratt, D.E., and Shaw, G.S.(2010) “Codon optimization for enhanced Escherichia coli expression of human S100A11 and S100A1 proteins.” Protein Expr. Purif. 73, 58-64.

Feng, C., Dupont, A.L., Nahm, N.J., Spratt, D.E., Weinberg, J.B., Guillemette, J.G., Salerno, J.C., Tollin, G., and Ghosh, D.K. (2009) “Intraprotein electron transfer in inducible nitric oxide synthase holoenzyme.” J. Biol. Inorg. Chem. 14, 133-142.

Spratt, D.E., Taiakina, V., Palmer, M., and Guillemette, J.G. (2008) “FRET conformational analysis of calmodulin binding to nitric oxide synthase peptides and enzymes.” Biochemistry 47, 12006-12017.

Spratt, D.E., Israel, O., Taiakina, V., and Guillemette, J.G. (2008) “Regulation of mammalian nitric oxide synthases by electrostatic interactions in the linker region of calmodulin.” Biochim. Biophys. Acta. 1784, 2065-2070.

Spratt, D.E., Taiakina, V., and Guillemette, J.G. (2007) “Calcium-deficient calmodulin binding and activation of neuronal and inducible nitric oxide synthases.” Biochim. Biophys. Acta. 1774, 1351-1358.

Spratt, D.E., Taiakina, V., Palmer, M., and Guillemette, J.G. (2007) “Differential binding of calmodulin domains to constitutive and inducible nitric oxide synthase enzymes.” Biochemistry 46, 8288-8300.

Spratt, D.E., Newman, E., Mosher, J., Ghosh, D.K., Salerno, J.C., and Guillemette, J.G. (2006) “Binding and activation of nitric oxide synthase isozymes by calmodulin EF hand pairs.” FEBS J. 273, 1759-1771.

Lang, S., Spratt, D.E., Guillemette, J.G., and Palmer, M. (2006) “Selective labeling of selenomethionine residues in proteins with a fluorescent derivative of benzyl bromide.” Anal. Biochem. 359, 253-258.

Lang, S., Spratt, D.E., Guillemette, J.G., and Palmer, M. (2005) “Dual-targeted labeling of proteins using cysteine and selenomethionine residues.” Anal. Biochem. 342, 271-279.

Newman, E., Spratt, D.E., Mosher, J., Cheyne, B., Montgomery, H.J., Wilson, D.L., Weinburg, J.B., Smith, S.M.E., Salerno, J.C., Ghosh, D.K., and Guillemette, J.G. (2004) “Differential activation of nitric-oxide synthase isozymes by calmodulin-troponin C chimeras.” J. Biol. Chem. 279, 33547-33557.