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The Perkins group has made dramatic advances in the use of Atomic Force Microscopes (AFMs) to study large single biomolecules, such as proteins and nucleic acids (DNA, RNA), that are important for life. After previously improving AFM measurements of biomolecules by orders of magnitude for stability, sensitivity and time response, the Perkins group has now developed ways to make these precision biomechanical measurements up to 100 times faster than previously possible––obtaining useful information in hours to days rather than weeks to months.

The Perkins group continues to extend the performance of its unique Atomic Force Microscope (AFM) technology, revealing for the first time a dozen new short-lived intermediate states in the folding and unfolding of a membrane protein that controls the exchange of chemicals and ions into and out of living cells. Measuring the energetics and dynamics of membrane proteins is crucial to understanding normal physiology and disease, and the Perkins group’s observation of multiple new folding/unfolding states shines new light on these cellular “gatekeepers.”

Ralph Jimenez received a Department of Commerce Bronze Medal for Superior Federal Service at a ceremony held in mid-December 2016. The Medal is the highest honor presented by the National Institute of Standards and Technology (NIST). Under Secretary of Commerce for Standards and Technology and NIST Director Willie E. May presided over the awards ceremony, which was held concurrently at NIST's Gaithersburg, Maryland, and Boulder, Colorado, campuses.

Far-red fluorescent light emitted from proteins could one day illuminate the inner workings of life. But before that happens, scientists like Fellow Ralph Jimenez must figure out how fluorescent proteins’ light-emitting structures work. As part of this effort, Jimenez wants to answer a simple question: How do we design red fluorescent proteins to emit longer-wavelength, or redder, light?

Because red fluorescent proteins are important tools for cellular imaging, the Jimenez group is working to improve them to further biophysics research. The group’s quest for a better red-fluorescent protein began with a computer simulation of a protein called mCherry that fluoresces red light after laser illumination. The simulation identified a floppy (i.e., less stable) portion of the protein “barrel” enclosing the red-light emitting compound, or chromophore. The thought was that when the barrel flopped open, it would allow oxygen in to degrade the chromophore, thus destroying its ability to fluoresce.