Enzymes Stepping on Landmines
| Date/Time: | Monday, 07 Mar 2016 from 4:10 pm to 5:00 pm |
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| Location: | Physics 0003 |
| Phone: | 515-294-5441 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
Abstract: Enzymes are proteins that are responsible for catalyzing reactions in living systems. Some enzymes perform reactions so exothermic that their own self-generated heat would be sufficient to unfold over a million small proteins per second. How do enzymes then cope with this heat? Here we will discuss recent work where we have shown that enzymes rapidly dissipate heat by accelerating their center of mass.
I will also discuss a recent method for addressing the 'single molecule counting problem which involves determining how many proteins of type X, say, are in a given complex in living cells.
Characterizing protein assemblies -- as they occur in their native cellular environment -- is a major challenge since these assemblies can involve up to many tens of proteins within approximately a 10nm range.
The method I present shows promise in characterizing protein complexes in living cells by using state-of-the-art (superresolution) data already available.
The method is also a first step in quantitatively characterizing protein-protein interactions which is an essential prerequisite for developing a mechanistic understanding of cell biology and the disease states associated with defective protein complexes.
BIO: Steve Pressé , Assistant Professor, Physics - While some may think of theoretical science as rigid (consider long equations with Greek symbols), to Assistant Professor of Physics Steve Pressé, science, especially biophysics, is an artistic endeavor (cue classical music) melding the elegance of physics with the intricate complexity of biology via the creative processes of observation and analysis.
Pressé, who joined the IUPUI faculty in 2013, has been asking questions and seeking answers for as long as he or anyone can remember; questions about science, about music, about anything and everything.
Growing up in Montréal, he queried his mother in Italian, his father in French and his teachers in English, later picking up German and Spanish along the way. By the time he entered McGill University, as a bio-organic chemistry major, his goal was to master the tools that he would need to answer his own questions. It was not until graduate school at MIT that he took his first physics course and was smitten with the discipline. He received his Ph.D. in chemical physics with a lot of statistical physics thrown in the mix, and moved from the East to the West Coast for a postdoctoral fellowship in biophysics at UCSF.
"People tend to think of physics as analytic and strictly quantitative. In high school and college it may seem rigid because there are certain rules you need to learn before taking the first creative steps into research. However, math and physics can narrate a deeply lyrical and textured story of how biology and the world around us work," Pressé says.
Pressé tries to convey the melody of the discipline as he teaches. At IUPUI, he is leading undergraduate problem-solving electro-magnetism theory lab sessions for physics and engineering majors, teaching a graduate course in biophysics and mentoring Ph.D. students and postdocs. In his biophysics lab, he is investigating how proteins function -- collaborating with scientists in a variety of disciplines -- writing and publishing papers on his work and, of course, applying for grants to carry his research forward.
"As physicists we have a bag of tools available to us, tools which are versatile and can solve an astounding array of problems. Yet no textbook can ever tell us precisely what tools, when brought together, will answer today's most pressing biological questions. It's a creative process like composing music," Pressé notes.
He balances his productive scientific pursuits with a deep fascination with Johann Sebastian Bach. Pressé has studied the violin since age six and is a self-taught harpsichordist. Following in the footsteps of the inspiring composer, he describes his scientific efforts as the study of the natural contrapuntal interplay between biology and physics.