A flash of insight: Chemist uses lasers to see proteins at work

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Binghamton University researcher Christof Grewer thinks he has an important brain transport protein -- glutamate transporter -- figured out and he's taking aim with lasers. Credit: Jonathan Cohen

Binghamton University researcher Christof Grewer thinks he has an important brain transport protein – glutamate transporter – figured out. And he's using a novel approach to spy on them by taking aim with lasers.

Grewer, a biophysical chemist, studies glutamate transport proteins, miniscule components of our brains that move glutamate among cells. Glutamate, an important molecule in cellular metabolism, is also a neurotransmitter. He explains his research on these tiny proteins in the brain using an analogy: imagine never having seen a car before and trying to determine what makes the vehicle run.

"We would be interested in seeing what happens when the car is moving, and we'd take pictures of that," he says. "We'd see the pistons moving, and that would be the beginning of understanding."

Scientists know the transport proteins are important, and they know they move glutamate in and out of cells through a sort of door in the cell wall, known as a glutamate transporter. But exactly how the proteins trigger those doors in the cell wall, and what makes them move glutamate to the inside or outside of a cell, is unknown.

Learning how those triggers function could have major implications for human health. For example, during a stroke, when blood and oxygen to the brain are restricted, brain cells release glutamate into the space surrounding them. That starts a toxic chain that can kill brain cells and harm certain brain functions. Knowing how the glutamate molecules are transported through cell walls could one day lead to drugs that help or halt the transport.

Grewer — one of perhaps two dozen researchers in the world who work on this problem — switches analogies as he continues describing the way these proteins move.

"Think about people being transported in an elevator in a tall building," he says. "So in order for that to work, the door of the elevator has to open, and then the person has to step into the elevator. And then the elevator brings you to a higher floor, and then the door has to open, and the person has to walk out."

In this case, glutamate molecules are the people. The elevator cars are the glutamate transporters. And the electricity and wires that move elevator doors are — well, that's what he's trying to figure out. Grewer's brainstorm was to create a method that uses lasers to trigger the transports' action. By controlling when the movement happens, he can document it. It all goes back to his analogy of photographing a car's pistons. Taking snapshots may illuminate how the transporters and glutamate molecules work together.

Grewer stumbled onto the glutamate transporters. When he was a graduate student in physical chemistry at Johann Wolfgang Goethe-University in Frankfurt, Germany, his research focused on chemistry and light. His introduction to biochemistry — and to glutamate receptors — came during a post-doctoral fellowship at
Cornell University.

"We were trying to activate these receptors on a very fast time scale," he says. "It's not that easy to do."

His background in chemistry and physics brought fresh insight to the lab. What if, he thought, a flash of light could help trigger the transport process? By timing the reactions, the researchers could better capture what happens during the glutamate transfer.

"They were so interesting to me that I just had to stay with them," Grewer says of glutamate transporters. "I thought, that is just the most amazing thing to study."

Most biochemical research on the brain focuses on possible cures and many researchers are experimenting with known drugs to judge their effect on brain function.

In most proteins, and in biology, researchers know what the genetic code and the DNA look like. The number of proteins in the body is also a known factor. But what's not unclear is how these proteins function. And that's where Grewer's work comes in. He has become a pioneer in the usage of lasers, which although used on other types of proteins, has not been used before in this area of study.

Provided by Binghamton University

A flash of insight: Chemist uses lasers to see proteins at work

Binghamton University researcher Christof Grewer thinks he has an important brain transport protein -- glutamate transporter -- figured out. And he's using a novel approach to spy on them by taking aim with lasers.

Grewer, a biophysical chemist, studies glutamate transport proteins, miniscule components of our brains that move glutamate among cells. Glutamate, an important molecule in cellular metabolism, is also a neurotransmitter. He explains his research on these tiny proteins in the brain using an analogy: imagine never having seen a car before and trying to determine what makes the vehicle run.

"We would be interested in seeing what happens when the car is moving, and we'd take pictures of that," he says. "We'd see the pistons moving, and that would be the beginning of understanding."

Scientists know the transport proteins are important, and they know they move glutamate in and out of cells through a sort of door in the cell wall, known as a glutamate transporter. But exactly how the proteins trigger those doors in the cell wall, and what makes them move glutamate to the inside or outside of a cell, is unknown.

Learning how those triggers function could have major implications for human health. For example, during a stroke, when blood and oxygen to the brain are restricted, brain cells release glutamate into the space surrounding them. That starts a toxic chain that can kill brain cells and harm certain brain functions. Knowing how the glutamate molecules are transported through cell walls could one day lead to drugs that help or halt the transport.

Grewer -- one of perhaps two dozen researchers in the world who work on this problem -- switches analogies as he continues describing the way these proteins move.

"Think about people being transported in an elevator in a tall building," he says. "So in order for that to work, the door of the elevator has to open, and then the person has to step into the elevator. And then the elevator brings you to a higher floor, and then the door has to open, and the person has to walk out."

In this case, glutamate molecules are the people. The elevator cars are the glutamate transporters. And the electricity and wires that move elevator doors are -- well, that's what he's trying to figure out. Grewer's brainstorm was to create a method that uses lasers to trigger the transports' action. By controlling when the movement happens, he can document it. It all goes back to his analogy of photographing a car's pistons. Taking snapshots may illuminate how the transporters and glutamate molecules work together.

Grewer stumbled onto the glutamate transporters. When he was a graduate student in physical chemistry at Johann Wolfgang Goethe-University in Frankfurt, Germany, his research focused on chemistry and light. His introduction to biochemistry -- and to glutamate receptors -- came during a post-doctoral fellowship at Cornell University.

"We were trying to activate these receptors on a very fast time scale," he says. "It's not that easy to do."

His background in chemistry and physics brought fresh insight to the lab. What if, he thought, a flash of light could help trigger the transport process? By timing the reactions, the researchers could better capture what happens during the glutamate transfer.

"They were so interesting to me that I just had to stay with them," Grewer says of glutamate transporters. "I thought, that is just the most amazing thing to study."

Most biochemical research on the brain focuses on possible cures and many researchers are experimenting with known drugs to judge their effect on brain function.

In most proteins, and in biology, researchers know what the genetic code and the DNA look like. The number of proteins in the body is also a known factor. But what's not unclear is how these proteins function. And that's where Grewer's work comes in. He has become a pioneer in the usage of lasers, which although used on other types of proteins, has not been used before in this area of study.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by Binghamton University, via EurekAlert!, a service of AAAS.

A new way to make lighter, stronger steel -- in a flash

A Detroit entrepreneur surprised university engineers here recently, when he invented a heat-treatment that makes steel 7 percent stronger than any steel on record – in less than 10 seconds.

In fact, the steel, now trademarked as Flash Bainite, has tested stronger and more shock-absorbing than the most common titanium alloys used by industry.

Now the entrepreneur is working with researchers at Ohio State University to better understand the science behind the new treatment, called flash processing.

What they've discovered may hold the key to making cars and military vehicles lighter, stronger, and more fuel-efficient.

In the current issue of the journal Materials Science and Technology, the inventor and his Ohio State partners describe how rapidly heating and cooling steel sheets changes the microstructure inside the alloy to make it stronger and less brittle.

The basic process of heat-treating steel has changed little in the modern age, and engineer Suresh Babu is one of few researchers worldwide who still study how to tune the properties of steel in detail. He's an associate professor of materials science and engineering at Ohio State, and Director of the National Science Foundation (NSF) Center for Integrative Materials Joining for Energy Applications, headquartered at the university.

"Steel is what we would call a 'mature technology.' We'd like to think we know most everything about it," he said. "If someone invented a way to strengthen the strongest steels even a few percent, that would be a big deal. But 7 percent? That's huge."

Yet, when inventor Gary Cola initially approached him, Babu didn't know what to think.

"The process that Gary described – it shouldn't have worked," he said. "I didn't believe him. So he took my students and me to Detroit."

Cola showed them his proprietary lab setup at SFP Works, LLC., where rollers carried steel sheets through flames as hot as 1100 degrees Celsius and then into a cooling liquid bath.

Though the typical temperature and length of time for hardening varies by industry, most steels are heat-treated at around 900 degrees Celsius for a few hours. Others are heated at similar temperatures for days.

Cola's entire process took less than 10 seconds.

He claimed that the resulting steel was 7 percent stronger than martensitic advanced high-strength steel. [Martensitic steel is so named because the internal microstructure is entirely composed of a crystal form called martensite.] Cola further claimed that his steel could be drawn – that is, thinned and lengthened – 30 percent more than martensitic steels without losing its enhanced strength.

If that were true, then Cola's steel could enable carmakers to build frames that are up to 30 percent thinner and lighter without compromising safety. Or, it could reinforce an armored vehicle without weighing it down.

"We asked for a few samples to test, and it turned out that everything he said was true," said Ohio State graduate student Tapasvi Lolla. "Then it was up to us to understand what was happening."

Cola is a self-taught metallurgist, and he wanted help from Babu and his team to reveal the physics behind the process – to understand it in detail so that he could find ways to adapt it and even improve it.

He partnered with Ohio State to provide research support for Brian Hanhold, who was an undergraduate student at the time, and Lolla, who subsequently earned his master's degree working out the answer.

Using an electron microscope, they discovered that Cola's process did indeed form martensite microstructure inside the steel. But they also saw another form called bainite microstructure, scattered with carbon-rich compounds called carbides.

In traditional, slow heat treatments, steel's initial microstructure always dissolves into a homogeneous phase called austenite at peak temperature, Babu explained. But as the steel cools rapidly from this high temperature, all of the austenite normally transforms into martensite.

"We think that, because this new process is so fast with rapid heating and cooling, the carbides don't get a chance to dissolve completely within austenite at high temperature, so they remain in the steel and make this unique microstructure containing bainite, martensite and carbides," Babu said.

Lolla pointed out that this unique microstructure boosts ductility -- meaning that the steel can crumple a great deal before breaking – making it a potential impact-absorber for automotive applications.

Babu, Lolla, Ohio State research scientist Boian Alexandrov, and Cola co-authored the paper with Badri Narayanan, a doctoral student in materials science and engineering.

Now Hanhold is working to carry over his lessons into welding engineering, where he hopes to solve the problem of heat-induced weakening during welding. High-strength steel often weakens just outside the weld joint, where the alloy has been heated and cooled. Hanhold suspects that bringing the speed of Cola's method to welding might minimize the damage to adjacent areas and reduce the weakening.

If he succeeds, his discovery will benefit industrial partners of the NSF Center for Integrative Materials Joining Science for Energy Applications, which formed earlier this year. Ohio State's academic partners on the center include Lehigh University, the University of Wisconsin-Madison, and the Colorado School of Mines.

Provided by The Ohio State University (news : web)