English, Brian P and Min, Wei and Oijen, Antoine M van and Lee, Kang Taek and Luo, Guobin and Sun, Hongye and Cherayil, Binny J and Kou, SC and Xie, X Sunney (2006) Ever-fluctuating single enzyme molecules: Michaelis-Menten equation revisited. In: Nature Chemical Biology, 2 (2). pp. 87-94.Full text not available from this repository. (Request a copy)
Enzymes are biological catalysts vital to life processes and have attracted century-long investigation. The classic Michaelis-Menten mechanism provides a highly satisfactory description of catalytic activities for large ensembles of enzyme molecules. Here we tested the Michaelis-Menten equation at the single-molecule level. We monitored long time traces of enzymatic turnovers for individual \beta-galactosidase molecules by detecting one fluorescent product at a time. A molecular memory phenomenon arises at high substrate concentrations, characterized by clusters of turnover events separated by periods of low activity. Such memory lasts for decades of timescales ranging from milliseconds to seconds owing to the presence of interconverting conformers with broadly distributed lifetimes. We proved that the Michaelis-Menten equation still holds even for a fluctuating single enzyme, but bears a different microscopic interpretation.
|Item Type:||Journal Article|
|Additional Information:||Copyright for this article belongs to Nature Publishing Group.|
|Department/Centre:||Division of Chemical Sciences > Inorganic & Physical Chemistry|
|Date Deposited:||14 Feb 2006|
|Last Modified:||27 Aug 2008 11:44|
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