Konermann tracks how proteins form to allow function
By Mitchell Zimmer
April 01, 2011
Lars Konermann is looking at the shape of proteins to come.
Currently, researchers find it quite routine to figure out the sequence of amino acids within the chains that make up various proteins. There are methods to visualize their final forms, but it is the process in between where there are a lot of unknowns.
“When proteins are first made, they are very long chains that are disordered,” says Konermann, recipient of this year's Florence Bucke Science Prize. “To be biochemically active, proteins have to fold into well defined and highly ordered structures.
“It’s not really understood how this works.”
Konermann’s group in The University of Western Ontario Chemistry Department is looking into the subtleties of how this folding occurs and, occasionally, fails causing diseases.
A deuterium atom reacts much like one of hydrogen but the difference is found in the atomic nuclei. Hydrogen has a single proton giving it the atomic mass of one while deuterium’s nucleus contains an additional neutron making its mass two.
This property is essential for Konermann’s work.
“For every hydrogen that gets switched with deuterium the protein mass increases by one,” he says. “That mass change is what we measure and this happens at many, many locations throughout the protein. What we really want to know is not only how many deuteriums have been exchanged but also where in the protein.”
These changes in mass depend on how the protein is shaped during folding.
“You have an unfolded protein and … all of the exposed amino acids will react. When the same protein is then folded, a lot of these amino acids will be shielded and they will not react with the chemical label,” he says. “The attachment of the chemical label changes the mass of the protein and this mass change depends of the structure. In this way we can learn something about the protein structure.”
Konermann’s lab quickly labels proteins as they fold at well defined time points, often just milliseconds apart. He says that the process is analogous to stop-motion animation where each time point provides a snapshot of what is happening.
“Then we piece these pictures together and we can follow the protein structural changes from unfolded to folded,” he says.
Konermann’s work adds a deeper understanding of how protein folding errors can lead to diseases. “Alzheimer’s is one disease where proteins misfold and then aggregate,” he says. It is these clumps of glued together proteins that cause the illness.
“We actually used the same deuterium method to look at the structure of these Alzheimer’s aggregates and we came up with some new structural insights that hopefully one day will help to battle this disease,” he continues. “So there are definitely long-term medical implications for all of these studies.”
The Florence Bucke prize, intended to recognize some of the best research in the Faculty of Science, is in memory of Florence Bucke (BA'26) who taught school in Fort Erie until 1971.
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