The Faculty


Structure and function of hormone-receptor interactions, enzyme-inhibitor interfaces, and synthetic proteins


B.S. (Chemistry and Mathematics) 1968, Davis and Elkins College

Ph.D. (Physical Chemistry) 1972, University of Delaware, Newark

Research Summary

1) One of our research interests centers around studying at atomic resolution the structural and functional properties that define molecular recognition systems that activate and regulate biological properties. In particular, we study the energetics of hormone-induced receptor activation and regulation of growth hormone and its receptor using X-ray crystallography, site-directed mutagenesis, phage display mutagenesis and biophysical analysis.

2) Synthetic Antibodies- We use novel phage display libraries and screening procedures to produce a new class of synthetic affinity binders (sABs) based on Fab antibody scaffolds. These synthetic antibodies are much more versatile than traditional monoclonal antibodies and can be tuned to bind to multi-protein complexes and specific conformational states of their protein targets. These attributes make them the reagents of choice to study complex processes like cell signaling and cytokinesis.

3) Drug delivery- We have developed a unique drug delivery method that utilizes ligand-induced receptor-mediated endocytosis pathways. We call this method Receptor-Mediated Delivery (RMD) and have shown that we can deliver functionally active proteins and RNA/DNA cargoes into live cells for functional and imaging experiments.

4) Synthetic biology- We use a combination of peptide synthesis and phage display (biosynthetic phage display) to produce proteins with novel properties.

Selected Publications

Rizk SS, Luchniak A, Uysal S, Brawley CM, Rock RS, Kossiakoff AA "An engineered substance P variant for receptor-mediated delivery of synthetic antibodies into tumor cells". Proc Natl Acad Sci USA (2009) 106(27):11011-5. 

Uysal S, Vasquez V, Tereshko V, Fellouse FA, Sidhu SS, Koide S, Perozo E, Kossiakoff AA "Crystal structure of full-length KcsA in its closed conformation". Proc Natl Acad Sci USA (2009) 106(16):6644-9. 

Mandal K, Pentelute BL, Tereshko V, Kossiakoff AA, Kent SB "X-ray structure of native scorpion toxin BmBKTx1 by racemic protein crystallography using direct methods". J Am Chem Soc. (2009) 131(4):1362-3. 

Horn, J.R., Sosnick, T.R., Kossiakoff, A. A. (2009) " Principal determinants leading to transition state formation of a protein-protein complex, orientation trumps side chain interactions" Proc. Natl. Aca. Sci. (USA) (2009) 106(8):2559-64. 

Ye, J.D., Tereshko, V., Frederiksen, J.K., Koide, A., Fellouse, F.A., Sidhu, S.S., Koide, S., Kossiakoff, A.A., Piccirilli, J.A. (2008) "Synthetic antibodies for specific recognition and crystallization of structured RNA" Proc. Natl. Acad. Sci. U.S.A 105(1): 82-7. 

Tereshko, V., Uysal, S., Koide, A., Margalef, K., Koide, S., Kossiakoff, A. A. (2008) "Toward chaperone-assisted crystallography: protein engineering enhancement of crystal packing and X-ray phasing capabilities of a camelid single-domain antibody (VHH) scaffold" Protein Sci 17(7): 1175-87. 

Walsh, S.T., Kossiakoff, A.A. (2006) "Crystal structure and Sit 1 binding energetics of human placental lactogen" J Mol Biol 358:773-84. 

Horn, J.R, Kraybill, B., Petro, E.J., Coales, S.J., Morrow, J.A., Hamuro, Y., Kossiakoff, A.A. (2006) "The role of protein dynamics in increasing binding affinity for an engineered protein-protein interaction established by H/D exchange mass spectrometry." Biochemistry 45: 8488-98. 

Pal, G., Kouadio, J.L., Artis, D., B. Kossiakoff, A.A., Sidhu, S. (2006) "Comprehensive and quantitative mapping of energy landscapes for protein-protein interactions by rapid combinatorial scanning " J Biol Chem 281: 22378-85 

Kouadio, J., Horn, J., Pal, G., Kossiakoff, A. A. (2005) "Shotgun alanine scanning shows that growth hormone can bind productively to its receptor through a drastically minimized interface." J. Biol. Chem. 280(27):3852-6. 

Pal, G., Kossiakoff, A. A., and Sidhu, S. S. (2003) "The functional binding epitope of a high affinity variant of human growth hormone mapped by shotgun alanine-scanning mutagenesis: Insights into the mechanisms responsible for improved affinity." J. Mol. Biol. 332: 195- 204.