Single enzymes twist and twitch over time.
Researchers at the Ames (Iowa) Laboratory have observed the behavior of individual enzyme molecules as they catalyze cat·a·lyze
To modify, especially to increase, the rate of a chemical reaction by catalysis.
to cause or produce catalysis. reactions. Weihong Tan and Edward S. Yeung trapped single molecules of the enzyme lactate dehydrogenase lactate dehydrogenase
n. Abbr. LDH
Any of a class of enzymes found in the liver, kidneys, striated muscle, and heart muscle that catalyze the reversible conversion of pyruvate and lactate. in two different types of vials: the pores of a membrane sold commercially as a filter and holes drilled into a quartz slide. Each vial held just one-thousandth of a trillionth tril·lionth
1. The ordinal number matching the number one trillion in a series.
2. One of a trillion equal parts.
tril of a liter of liquid.
By monitoring the fluorescent products of the enzyme reaction, the team saw that a single enzyme molecule can change its behavior over the course of a couple of hours. "One molecule can suddenly switch to a higher reaction rate, then go back to what it was before," Yeung says.
The switching probably results when the enzyme twists into different conformations as it interacts with the walls of the vial, he explains. Drugs designed to target these other forms might show greater efficacy. The report appears in the Oct. 15 Analytical Chemistry analytical chemistry: see under chemistry. .