In the realm of structural biology, advancements in cryo-electron microscopy (cryo-EM) have revolutionized understanding of biological molecules and cellular structures at the atomic level.
Structural biologist Tina Izard, Ph.D., a professor in the chemistry department at The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, has discovered many new biological structures fundamental to life with the technology. See those structures here.
Viewing a protein’s structure for the first time—seeing its arrangement of atoms, how it folds into origami-like shapes and how those shapes dictate the protein’s role in the living organism—that’s the thrill of discovery that motivates Izard.
“The first time I saw a three-dimensional structure, it just took my breath away,” Izard said.
A human hair is about 29,000 nanometers wide. A red blood cell is about one-fifth that width, around 6,000 nanometers. Light microscopes, at their limits, enable visualization of things the size of a bacterium, as small as about 200 nanometers.
The proteins that Izard studies are about 16 times smaller than that. A light microscope won’t do the job. Standard transmission electron microscopes can visualize static things that small, but they destroy biological molecules in the process. Cryo-electron microscopy has made visualization of these tiny biomolecules possible.
Helping Scientists Investigate Life
The director of the Structural Biology / Cryo-Electron Microscopy Core at The Wertheim UF Scripps Institute is Anjelique Sawh-Gopal, who arrived here from a previous post at the New York Structural Biology Center. Sawh-Gopal had served as research associate at the center, which was founded by a consortium of nine research institutions. She helped scientists from around the nation discover new molecular structures.
How to access the microscope
Cryo-EM Services, Scheduling and Rates
For more information about the instrumentation, computing resources, sample preparation steps and more, visit the Structural Biology Cryo-EM Core page.
Sawh-Gopal says her top goals here are to make sure the institute’s impressive Jeol CryoARM300 microscope is performing at its best, and is available to researchers when they need to use it, enabling many more discoveries. Since arriving, Sawh-Gopal has built a new Structural Biology / Cryo-EM Core web page, created a system for billing, and worked with the microscope’s manufacturer to ensure the instrument is upgraded to the latest standards.
Sawh-Gopal offered these tips for labs that would like to use the microscope for their next structural study:
- Make sure you have the supplies necessary for your sample preparation ahead of time. This includes purchasing the grids that are to be frozen and loaded into the microscope. It also includes making a plan to freeze the sample. Devices called plunge freezers are required to immerse samples into a bath of liquid ethane. Two labs on campus currently have plunge freezers: Tina Izard, Ph.D., and Kirill Martemyanov, Ph.D..
- Make arrangements with UFIT in advance for data storage and transfer through Globus. You’ll need at least 3 terabytes for your imaging efforts.
- Have a designated person in the lab trained to use data processing software such as cryoSPARC or RELION.
Sawh-Gopal said her journey into the world of structural biology began during her undergraduate pre-med studies at City University of New York, where she found a passion for unraveling the mysteries of life at a molecular level. When doctors would prescribe a medication, she wanted to understand why – what were the cellular mechanisms? She pursued a master’s degree in biology at City College of New York, where her thesis was on ultra structures of the visual cortex. Her thesis work required her to spend long hours at the New York Structural Biology Center. Eventually, it turned into a job.
“Every microscope that came my way, I took the time to learn”, she said. “On campus I left knowing how to operate pretty much every piece of microscope equipment.”
It was seeing the technology advance year after year, the resolutions of the molecules imaged becoming smaller and smaller, that made her excited to work in the structural biology field.
“I think it’s amazing that we can even see a protein,” Sawh-Gopal said. “How they bind to other things, how they form these complexes? It constantly astonishes me.”
So far, she’s pulled images from the Jeol CryoARM300 that approaches 2 angstroms in resolution. An angstrom is one ten-billionth of a meter. For an idea of how small that is, understand it would take about one million angstroms to cross the width of a human hair.
In addition to managing the Cryo-EM facility, Sawh-Gopal said she can help researchers schedule access to the institute’s X-Ray Crystallography equipment, which is an efficient way to gain structural information about molecules, so long as they are amenable to crystallization.
Beyond assisting researchers, she enjoys mentoring and nurturing the next generation of scientists. She says her door is always open to students and trainees with questions. Troubleshooting technical challenges is a part of the job she loves. She recalled one project that involved light-sensitive proteins. The samples kept clumping, so they tried making their sample in completely dark conditions, to no avail. They eventually found that working in red light solved that problem.
“I like when things turn out well, especially if the user has been struggling with their project. When you get something to work, it just feels amazing.”