Department of Molecular and Cellular Biology Faculty . Dr. Steffen Graether

Steffen Graether



Email:
graether@uoguelph.ca

Office: SSC 2255
Ext: 56457
Lab: SSC 2205
Ext: 54590

Graduate Student Opportunities

Profile

I enrolled in a biochemistry major in my third of undergraduate studies. I enjoyed chemistry and found biology to be fascinating, so studying these two subjects in one discipline really interested me. I began to appreciate that complex biological process can be understood in terms of the interaction of proteins and other biological molecules, an idea which still intrigues me to this day.

During my graduate studies, I studied diverse protein/ligand systems, including amyloid (Alzheimer) proteins interacting with basement membrane proteins, and the role of calmodulin and caldesmon in smooth muscle regulation. But the breakthrough came when I joined a crystallography lab and began to look at how antifreeze proteins can interact with ice crystals. The power to ‘see’ proteins at the atomic level amazed me, and gave me the tools to understand protein interactions at a very fundamental level.

My interest in protein structures expanded as a post-doctoral fellow, where I learned how to use NMR (nuclear magnetic resonance) to study proteins. NMR is an extremely powerful technique for understanding protein structure and function, especially since it is able to characterize the flexibility of biological molecules. NMR also lends itself to the detailed study of protein/ligand interactions, and is able to characterize proteins both in solution and in a solid such as ice or membranes.

Education

B.Sc.(Hons) - Queen’s University
Ph.D. - Queen’s University
Postdoctoral Fellow - University of Alberta

Research

My enthusiasm for studying antifreeze proteins has continued as an independent investigator. These intriguing proteins are found in a number of cold-environment organisms such as fish, insects, plants and bacteria. Though the freezing point is thought to be depressed through the “Kelvin Effect”, it is still unclear after many years of study how the protein binds to the ice surface. Our group is interested in understanding how antifreeze protein binds to its ligand. We are studying the protein both in solution and in ice using NMR, and will test our models by measuring antifreeze activity of mutated and modified proteins.

A second project involves the study of another stress-response protein known as dehydrin. These proteins are expressed in plants during times of desiccative stress, and are thought to bind water, protect the cellular membrane from drying and prevent proteins from denaturing. Dehydrins are predicted to be “intrinsically disordered proteins” (IDPs), meaning that they do not have a defined structure as we understand it. We are using NMR to characterize the flexibility of dehydrins and understand how they function.

Selected Publications

Hughes, S. and Graether, S.P. (2011) Cryoprotective mechanism of a small intrinsically disordered protein. Protein Sci. 20:42-50

Patel, S.N. and Graether, S.P. (2010) Increased flexibility decreases antifreeze protein activity. Protein Sci. 19:2356-2365

Patel, S.N. and Graether, S.P. (2010) Structures and ice-binding faces of the alanine-rich type I antifreeze proteins. Bioc. Cell Biol. 88:223-229

Findlater, E.E. and Graether, S.P. (2009) Resonance assignments of the intrinsically disordered K2 and YSK2 dehydrin proteins. Biomol. NMR Assign. 3:273-275

Livernois, A.M., Hnatchuk, D.J., Findlater, E.E., and Graether, S.P. Obtaining highly purified intrinsically disordered protein by boiling lysis and single step ion exchange. Anal. Biochem. (2009) 392:70-76

Teaching

BIOC*3560 - Structure and Function in Biochemistry
MCB*6370 - Protein Structural Biology and Bioinformatics

Graduate Students

Stephanie Hughes
Majid Hassas Roudsari (co-supervised, Doug Goff)

Undergrad Students

Erik Tralman-Baker
Verena Schart

Links

At Guelph article


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