MMP enzymes produce 'molecular scissors'.

• Position: Antibodies - Matrix metalloproteinases

Enzymes--the proteins responsible for chemical reasons in living cells--change their structure at dizzying speeds. This dynamic action makes them very efficient, but difficult to study. Prof. Irit Sagi of the Department of Biological Regulation at Israel's Weizmann Institute of Science has developed new experimental tools and procedures to study shape-shifting enzymes in real time and at the scale of individual atoms.

"For the past 11 years, we've been especially fascinated by enzymes called matrix metalloproteinases, or MMPs, that act like molecular scissors. They chop and dice tissue components like collagen and gelatin. We want to understand the molecular mechanisms that drive the chemical reactions of these enzymes."

Since MMPs play a role in cancer, inflammatory diseases, and autoimmune disorders, Sagi and her research team investigate ways to inhibit their activity. The goal is to design new drugs that can block the action of specific MMPs. Such drugs potentially could be used to treat a wide variety of illnesses, including colon cancer, multiple sclerosis, Crohn's disease, and rheumatoid arthritis.

Sagi and her colleagues have developed an innovative technique that enables them to track complex changes precisely as they actually take place in an enzyme. The method, which works in...