Fluorescence from a Moving Target

See allHide authors and affiliations

Science  10 Oct 2003:
Vol. 302, Issue 5643, pp. 193
DOI: 10.1126/science.302.5643.193c

Electron-transfer (ET) reactions are highly distance dependent, and thus conformational changes within an enzyme might leave their signature on the rates of individual steps. Complex multiexponential decays would be expected, but ensemble-average measurements might show this behavior simply because a heterogenous population is being probed. Yang et al. (p. 262; see the Perspective by Orrit) have followed the quenching of fluorescence of a flavin group in a flavin reductase and observed nonexponential decays from single molecules. These results support the idea that enzymes may dynamically convert between conformers that have different reactivities.

Navigate This Article