Samba Virus Mapped With Cryo-EM
Kristin Parent, assistant professor of biochemistry and molecular biology, took a DIY approach to build a retrofitted cryo-electron microscope that allowed them to map a giant Samba virus – one of the world’s largest viruses. Courtesy of MSU
In a laboratory at Michigan State University, scientists took a DIY approach to build a retrofitted cryo-electron microscope that allowed them to map a giant Samba virus – one of the world’s largest viruses.
“If the common cold virus is scaled to the size of a ladder, then the giant Samba virus is bigger than the Washington Monument,” said Kristin Parent, assistant professor of biochemistry and molecular biology and co-author of the paper featured on the cover of the journal Viruses. “Cryo-EM allowed us to map this virus’ structure and observe the proteins it uses to enter, or attack, cells.”
It seems counterintuitive that bigger organisms are harder to see, but they are when using cryo-electron microscopy. That’s because these microscopes usually are used to look at thin specimens and can’t decipher larger organisms to reveal their biological mechanisms. For thick samples, scientists see only dark gray or black blobs instead of seeing the molecular framework.
Read more: greater resolution imaging with Cryo-EM
Cryo-EM allowed Parent’s team to image the giant Samba virus and understand the structures that allow it to enter an amoeba. Once inside, Samba opens one of its capsid layers and releases its nucleocapsid – which carries the genetic cargo that sparks an infection. While Samba isn’t known to cause any diseases in humans, its cousin, the mimivirus, may be a culprit for causing some respiratory ailments in humans.
“If you scoop up a handful of water from Lake Michigan, you are literally holding more viruses than there are people on the planet,” said Parent, who published the paper with Jason Schrad and Eric Young, MSU biochemistry and molecular biology graduate students. “While scientists can’t study every virus on Earth, the insights we glean from viruses like the giant Samba can help us understand the mechanisms of other viruses in its family, how they thrive and how we can attack them.”
Read more: computer game graphics cards enable imaging of tiny structures
As bacteria become more resistant to antibiotics, looking for new ways to fight diseases will continue to grow in importance. Parent’s lab also studies how bacteria-infecting viruses enter cells using this method, which could potentially lead to new antibacterial treatments. Yet the world’s best cryo-EM microscope costs more than $5 million. Limited by funds but not drive, Parent was able to upgrade an existing microscope at MSU to do cryo-EM – one that is a tinkerer’s dream.
This traditional transmission electron microscope was retrofitted with a cryostage, which keeps viruses frozen in liquid nitrogen while they’re being studied. Parent and her team then added a Direct Electron DE-20 detector, a powerful camera – the mighty microscope’s piece de resistance.
Read more: building a Cryo-EM scope
Parent didn’t invent cryo-EM, but establishing it on campus serves as a viable proof-of-concept for MSU, opening the door for many interdisciplinary partnerships. This cutting-edge microscopy has applications across many fields, from those addressing a single protein to others studying entire cells. Virtually anyone studying complex molecular machines can advance their work with this tool, Parent added.
Parent has earned an AAAS Marion Milligan Mason Award for Women in the Chemical Sciences. This award, her paper in Viruses and being the co-author who performed cryo-EM work in a recent Nature Communications paper, lays the groundwork to someday have a more advanced cryo-EM microscope housed at MSU to be able to perform high-resolution structural studies.
“We’ve done quite a bit with our limited resources, but we’re primed to do more,” Parent said. “I think MSU could serve as a cryo-EM center and to increase the prevalence of this technology in the Midwest and beyond.”
This article has been republished from materials provided by Michigan State University. Note: material may have been edited for length and content. For further information, please contact the cited source.
Schrad, J., Young, E., Abrahão, J., Cortines, J. and Parent, K. (2017). Microscopic Characterization of the Brazilian Giant Samba Virus. Viruses, 9(2), p.30.
Auto Industry Tip Improves Smoked FoodNews
Infusing foods with smoke can impart delicious flavors, but could also come with an unwelcome side of carcinogens. To reduce the carcinogen content of smoked foods, researchers took a lesson from the automobile industry, running the smoke through a zeolite filter to remove harmful compounds. It worked, and with a happy bonus: superior smoke flavor.READ MORE
Test For Designer Drugs Could Help Treat Overdose PatientsNews
Medical professionals are scrambling to meet the growing demand for emergency room treatment, but they’re hampered by the lack of a quick and easy test to screen patients for “designer” drugs. Chemists have now developed such a test and are refining it with the hope that hospitals could eventually use it to choose the appropriate treatment.READ MORE
Promise for Combating Harmful Algal BloomsNews
A cheap, safe and effective method of dealing with harmful algal blooms is on the verge of being introduced following successful field and lab tests. Moves to adopt use of hydrogen peroxide (H2O2) as an effective treatment against toxic algae are already underway following the results of new research.READ MORE
Comments | 0 ADD COMMENT
World Congress on Advanced Pharmacy and Clinical Research
Jul 16 - Jul 17, 2018
11th International Conference and Exhibition on Metabolomics & Systems Biology
May 17 - May 19, 2018
6th Annual Congress on Biology and Medicine of Molecules
Sep 17 - Sep 18, 2018