The work, presented in the Aug. 29 edition of Science, marks the first time protein-folding kinetics has been monitored on the single-molecule level. Proteins are long chains of amino acids. Like shoelaces, they loop about each other or fold in a variety of ways, and only one way allows the protein to function properly. Just as a knotted shoelace can be a problem, a misfolded protein can do serious damage. Many diseases, such as Alzheimer's, cystic fibrosis, mad cow disease and many cancers result from misfolded protein.
Livermore's Lawrence postdoctoral fellow Olgica Bakajin worked with scientists from the NIDDK Laboratory of Chemical Physics at the National Institute of Health and the Physikalische Biochemie Universitt Postadam in Germany to develop a microfluidic mixer for studies of protein folding. With this mixer, researchers were able to access information about the protein folding reaction that was never available from ensemble measurements or even from the newer single molecule equilibrium measurements.
"For the first time, in this experiment we were able to look at a protein on a single molecule level at defined times after the folding reaction was initiated," Bakajin said. "With this method we are able to see and isolate intermediate states that under equilibrium conditions only exist for a brief period of time.
"This is a fundamental science project. We would like to understand the sequence of events through which a protein goes from a random coil to its functional 'folded' form, and we've designed an instrument that can
Contact: Anne Stark
University of California - Berkeley