UT Arlington researchers have been awarded a $300,000 National Science Foundation grant to study a new model for how motor proteins behave in the body.

Their study could radically change the face of biology by explaining how proteins move and interact with other biological systems, said Jean-Pierre Bardet, dean of the UT Arlington College of Engineering.

"If proven, their study could radically change the face of engineering and science at the nano scale and our understanding of the dynamics and movement of very small objects in a fluid environment," Bardet said.

Alan Bowling, an assistant professor in the Mechanical and Aerospace Engineering Department, is the lead investigator. Samarendra Mohanty, assistant professor of physics, and Subhrangsu Mandal, an associate professor of chemistry and biochemistry, are co-principal investigators in the project.

The NSF award is funded through the Early Concept Grants for Exploratory Research, or EAGER program. The grants are used to support exploratory work in its early stages on untested, but potentially transformative, research ideas or approaches.

Bowling contends that mass and acceleration make a difference at the nano level. The most widely accepted thinking and teaching omits mass and acceleration from the model, making it possible to violate Newton's second law, which states that force equals mass times acceleration.

"We think you have to account for that law," Bowling said. "We believe it makes a difference in whatever predictions you are using the model to obtain concerning the protein's behavior."

Bowling said the challenge in modeling such protein behavior at the nano level is that doing so lengthens the computer simulation time needed to perform the necessary calculations. Several modeling approaches result in computer simulations that can take several days or weeks to obtain the required data. Bowling said that his new modeling approach satisfies Newton's second law without sacrificing accuracy while keeping the computer simulation time down to several minutes.

Bowling describes motor proteins as nature's engine.

"They are the nano-sized chains of molecules in our body that convert chemicals obtained from the food we eat into mechanical work, in other words, movement," he said.

Thousands of motor proteins in human muscles perform ratcheting movements, where they alternately lock and dock into, then release muscle fibers that combine to produce muscle contractions.

Bowling said that the combination of movements of those tiny molecules creates all of the large motions that the human body can produce.

"The motor proteins are too small to see using a conventional optical microscope," Bowling said. "We'll be using laser light to measure how the motor proteins lock into the muscle fiber."

Mohanty has developed laboratory tools that can measure how the motor proteins ratchet into the muscle fiber.

"We use this highly intense light source confined to a very thin region that allows capture of the motor protein's movements at a rate fast enough, and at a length scale small enough, to discern whether the motor protein exhibits the locking behaviors predicted by the model," Mohanty said. "These measurements are not possible to perform using conventional microscopy techniques and will be highly challenging even with any existing advanced microscopes."

Mandal's expertise is in biochemistry and he will assist the team in synthesizing and sustaining the life of biological molecules, such as motor proteins, in a laboratory environment.

Bowling said the team would measure when motor proteins prepare to lock or dock into a substrate, such as a muscle fiber. The action is extremely quick, taking place in about 0.4 milliseconds.

"The new model predicts a point in time when the motor proteins are oscillating before docking," Bowling said. "Those oscillations are what we will measure."

Dean Bardet said Bowling's research is exactly what the EAGER program was built for. "It could provide a novel perspective in nanotechnology," Bardet said.

Posted June 27, 2012