Abstract:
:The electrical membrane potential (Vm) is one of the components of the electrochemical potential of protons across the biological membrane (proton motive force), which powers many vital cellular processes. Because Vm also plays a role in signal transduction, measuring it is of great interest. Over the years, a variety of techniques have been developed for the purpose. In bacteria, given their small size, Nernstian membrane voltage probes are arguably the favorite strategy, and their cytoplasmic accumulation depends on Vm according to the Nernst equation. However, a careful calibration of Nernstian probes that takes into account the tradeoffs between the ease with which the signal from the dye is observed and the dyes' interactions with cellular physiology is rarely performed. Here, we use a mathematical model to understand such tradeoffs and apply the results to assess the applicability of the Thioflavin T dye as a Vm sensor in Escherichia coli. We identify the conditions in which the dye turns from a Vm probe into an actuator and, based on the model and experimental results, propose a general workflow for the characterization of Nernstian dye candidates.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Mancini L,Terradot G,Tian T,Pu Y,Li Y,Lo CJ,Bai F,Pilizota Tdoi
10.1016/j.bpj.2019.10.030subject
Has Abstractpub_date
2020-01-07 00:00:00pages
4-14issue
1eissn
0006-3495issn
1542-0086pii
S0006-3495(19)30879-3journal_volume
118pub_type
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