Multi‐scale calcium (Ca2+) dynamics, exhibiting wide‐ranging temporal kinetics, constitutes a ubiquitous mode of signal transduction. We report a novel endoplasmic‐reticulum (ER)‐targeted Ca2+indicator, R‐CatchER, which showed superior kinetics in vitro (
Fluorescence‐activating proteins (FAPs) that bind a chromophore and activate its fluorescence have gained popularity in bioimaging. The fluorescence‐activating and absorption‐shifting tag (FAST) is a light‐weight FAP that enables fast reversible fluorogen binding, thus advancing multiplex and super‐resolution imaging. However, the rational design of FAST‐specific fluorogens with large fluorescence enhancement (FE) remains challenging. Herein, a new fluorogen directly engineered from green fluorescent protein (GFP) chromophore by a unique double‐donor‐one‐acceptor strategy, which exhibits an over 550‐fold FE upon FAST binding and a high extinction coefficient of approximately 100,000 M−1 cm−1, is reported. Correlation analysis of the excited state nonradiative decay rates and environmental factors reveal that the large FE is caused by nonpolar protein−fluorogen interactions. Our deep insights into structure‐function relationships could guide the rational design of bright fluorogens for live‐cell imaging with extended spectral properties such as redder emissions.
more » « less- Award ID(s):
- 2003550
- NSF-PAR ID:
- 10230265
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 27
- Issue:
- 35
- ISSN:
- 0947-6539
- Page Range / eLocation ID:
- p. 8946-8950
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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