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Eine neue Pulssequenz: Die Abstände zwischen Kupferzentren der homotrimeren Nitrit ‐ Reduktase wurden mit EPR ‐ Spektroskopie bestimmt (siehe Bild). Die Differenzen in der Elektronenspinrelaxation der Kupferionen ermöglichen das selektive Entfernen von Abständen aus der komplexen Abstandsverteilung. Diese Filtertechnik in Kombination mit PELDOR ‐ Experimenten dürfte bei Abstandsbestimmungen mittels EPR ‐ Spektroskopie hilfreich sein. [ABSTRACT FROM AUTHOR]

A new pulse sequence: The distances between copper sites of the homotrimeric Cu‐containing nitrite reductase were determined by EPR spectroscopy (see picture). By exploiting the differences in the electron spin relaxation of the Cu ions, a filtering technique allows the selective removal of distances from a complex distance distribution. This filter technique combined with the PELDOR experiment promises to be useful for distance mapping by EPR spectroscopy. [ABSTRACT FROM AUTHOR]

Single-molecule measurements are a valuable tool for revealing details of enzyme mechanisms by enabling observation of unsynchronized behavior. However, this approach often requires immobilizing the enzyme on a substrate, a process which may alter enzyme behavior. We apply a microfluidic trapping device to allow. for the first time, prolonged solution-phase measurement of single enzymes in solution. Individual redox events are observed for single molecules of a blue nitrite reductase and are used to extract the microscopic kinetic parameters of the proposed catalytic cycle. Changes in parameters as a function of substrate concentration are consistent with a random sequential substrate binding mechanism. [ABSTRACT FROM AUTHOR]