open access

https://hdl.handle.net/2115/51590

Dynamic Disorder in Single-Enzyme Experiments: Facts and Artifacts

英語

protein dynamics

2012-01-24

American Chemical Society

ACS Nano

6(1)

346-354

Using a single molecule fluorescence approach, the time series of catalytic events of an enzymatic reaction can be monitored yielding a sequence of fluorescent "on"- and "off"-states. An accurate on/off-assignment is complicated by the intrinsic and extrinsic noise in every single molecule fluorescence experiment. Using simulated data, the performance of the most widely employed binning and thresholding approach was systematically compared to change point analysis. It is shown that the underlying on- and off-histograms as well as the off-autocorrelation are not necessarily extracted from the "signal" buried in noise. The shapes of the on- and off-histograms are affected by artifacts introduced by the analysis procedure and depend on the signal-to-noise ratio and the overall fluorescence intensity. For experimental data where the background Intensity is not constant over time we consider change point analysis to be more accurate. When using change point analysis for data of the enzyme α-chymotrypsin, no characteristics of dynamic disorder were found. In light of these results, dynamic disorder might not be a general characteristic of enzymatic reactions.

学術雑誌論文

Accepted Manuscript

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright c2012 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/nn203669r

1936-0851