Dr. Neuenschwander, an associate professor of biochemistry at the University of Texas Health Center at Tyler, and his team are investigating one step in the blood-clotting process that involves factor IXa, an enzyme. Enzymes are proteins that change the rate of chemical reactions without needing an external energy source, such as heat.

“If you do not have factor IXa, you have hemophilia, or excessive bleeding, and your blood doesn’t clot properly. So you have to have factor IXa, but not too much of it. If it is left unregulated, you get clots where you do not want them and end up with strokes and heart attacks,” Dr. Neuenschwander said.

The research shows that a physiologically relevant molecule, heparin, can modulate the activity of factor IXa. Heparin is a naturally occurring mixture of compounds that prevents unwanted blood clotting. It is a molecule with many places where enzymes and other substances can bind to activate or stop biochemical reactions in the cell.

By revealing how factor IXa works, it should be possible to make synthetic chemicals that prevent strokes and heart attacks, Dr. Neuenschwander said. Conversely, you could make synthetic activators that could stop the unwanted bleeding that occurs in hemophilia, he added.

Dr. Neuenschwander and his team plan to spend the next year experimenting with antithrombin, a small naturally occurring molecule that inactivates several enzymes involved in the coagulation process. They hope to gain understanding of another step in that process.

“We want to see if we can design inhibitors that would mimic what heparin does. Our goal is to develop these and eventually test them in clinical trials,” Dr. Neuenschwander said.

MEDICA.de; Source: University of Texas Health Center at Tyler