Caught in the act: The dynamic dance ...( Waltham MAIn a new study in Nature B...),Health

Waltham, MAIn a new study in Nature, Brandeis University Howard Hughes Medical Investigator Dr. Dorothee Kern and collaborators pull back the curtain on the secret lives of enzymes, the ubiquitous proteins that catalyze chemical reactions in the cell. Harnessing a slew of sophisticated technologies to capture a key enzyme changing shape in near real time, Kern was able to show that these proteins are not the wallflowers of the biological world scientists had once thought, essentially passive until catalysis occurs. Rather, Kern and her team demonstrated that the enzyme adenylate kinase, and presumably many more, engages in a dynamic dance even before its catalytic datethe substrate to which it bindsshows up.

If one of the constants of life is change over time, implicit in this truth is how macroscopic change, such as the growth of a child, is ultimately rooted in microscopic change, such as atoms moving in a protein. Kerns study is remarkable in its ability to document the tiny flutterings of enzymes just before they do their all important catalytic work.

In two Nature articles, Kern and collaborators were able, in effect, to create a motion picture of an enzyme as it actually changed shape, or conformations, in the absence of the substrate. Its really a paradigm shift, said Kern. Earlier studies had been able only to create snapshots of enzymes frozen in time, obscuring their true restless, twitching selves.

The three-year study represents a breakthrough in scientific understanding of the dynamic personalities of enzymes. For years, Kern has dedicated herself to capturing how enzymes move and change shape through time. She pioneered the use of nuclear magnetic resonance (NMR), which can detect the motion of individual atoms in a protein, in this biophysical application.

But in this study, Kern, who earlier in life was the point guard on the East German national womens basketball team, knew she had to create a gold-standar
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