Research Interests: Structure and dynamics of membranes and proteins using X-ray and neutron scattering techniques.
Bowling for proteins
Biophysics and bowling might not seem like they have much in common, but researchers at McMaster University are using the same concept behind knocking down pins with a bowling ball to better understand how cell membranes work at the molecular level. Even after decades of research, cell membranes remain a mystery. Measuring the precise movement of proteins within a cell membrane is challenging because they cannot be easily “seen” due to their small size and rapid speed.
“We developed a tool to understand those processes on very small length scales,” said Maikel Rheinstadter, associate professor of physics in the Department of Physics and Astronomy. Neutron scattering enables researchers to study these movements by firing a neutron beam at the proteins, causing them to scatter like pins in a bowling alley. Since the neutrons move with the same energy as the proteins, the impact when they collide is so dramatic that it can be measured. Understanding how proteins move within a cell membrane and communicate with each other is an important step towards understanding macromolecular and cellular function. This knowledge can also be applied to bioengineering and pharmaceutical development such as improving drug transportation.
Proteins act like gatekeepers: they control what enters and leaves the cell. “They make sure that good things are transferred through the membrane to feed the cell and bad things stay out,” Rheinstadter explained. “We hope to use this knowledge to enhance or diminish the function of certain proteins.”
Proteins can be a cell’s best friend or worst enemy. Some proteins help defend the cell against disease while others can create holes in the cell membrane, causing the cell to die. Proteins are the first victims of infectious diseases. By understanding how proteins function at the molecular level, scientists can better understand how cells are damaged or die as a result of infectious diseases, which can lead to the development of more effective drugs.
After completing his PhD in condensed matter physics, Rheinstadter became interested in biophysics because he “wanted to do something more relevant,” but as he flipped through the pages of a biophysics textbook, his interest turned to disappointment.
“Everything had been done and discovered,” he said. Looking at the diagrams, he thought, “No one has seen this happen. These mechanisms are so small and the movements are so fast that we can’t look at them with a microscope or magnifying glass. Hardly anything has been seen, measured or quantified. This is what I thought I could do: come up with new, more powerful techniques to observe these fast motions.” He hopes these techniques will someday be used to develop better drugs.
Rheinstadter joined McMaster University in 2009 after completing research and academic appointments in Germany, France and the United States. “It’s a very good school with very positive energy in the department,” he said. “The people are outstanding, very friendly and helpful.”
Supervisor Letter:
Maikel Rheinstadter
Department of Physics & Astronomy
McMaster University
Dear Prospective Graduate Student,
One of the major challenges of modern physics is how to contribute to biology and life-sciences including the emerging biotechnology and biomedical device industries, functional foods and nutraceuticals, but also the development of new biomaterials and pharmaceutical developments. There is a huge potential yet to unleash. In our Laboratory for Membrane and Protein Dynamics, we use X-ray and neutron scattering techniques to study molecular structure and dynamics in synthetic and biological tissue. We investigate for instance interaction of common drugs with biological tissue of different composition mimicking brain-like or muscle-like tissue. We also study more fundamental aspects such as motion of lipids and proteins in membranes and formation and properties of nanodomains, so-called rafts. Current projects include developing molecular models for the low-dose aspirin therapy and functioning of common drug enhancers. Our laboratory is equipped with a biophysical preparation facility and operates BLADE (Biological Large Angle Diffraction Experiment), Canada’s most powerful in-house X-ray diffractometer dedicated to membrane research. From the high resolution X-ray diffraction experiments we determine the molecular structure of biological tissue: (1) the out-of-plane structure of the membrane to determine the precise location of the different molecules in the membrane with sub-nanometer resolution and (2) the lateral organization of the different molecular components in the plane of the membrane. You are welcome to explore our research web page if you want to find out more about our research.
As a student in my group you will be trained to work in a biophysical preparation suite and use unique in-house scattering instruments, such as a BLADE. We also use scattering infrastructure at large scale facilities, such as the Canadian Neutron Beam Centre (CNBC) at Chalk River, the Spallation Neutron Source (SNS) in the US, ISIS in the UK and the ILL in France. You will develop excellent organization and teamwork skills to prepare and conduct experiments at these facilities and interact with outstanding scientists. Experiments using the in-house equipment will give you the time to develop your experimental skills.
You will learn to work in a team, however, take the lead in your own research project. The outcome of your work will be published in high impact research journals. This is a very important part of your training and will set the foundation for your future career. You will learn to combine your creativity, your intellect, and hard work to accomplish your discoveries.
You will also have the opportunity to present your work at national and international conferences and workshops such as the Biophysical Meeting and the American Physical Society’s March Meetings, and more specialized neutron and membrane conferences. These experiences will not only build the reputation of the group as a whole, but also your own reputation and training as a young scientist.
If you are interested in joining our team, please contact me at rheinstadter@mcmaster.ca to discuss the possibilities. I will be more than happy to tell you more about potential projects.
I look forward to hearing from you,
Maikel Rheinstadter