A Single Fluorescent Protein-Based Indicator with a Time-Resolved Fluorescence Readout for Precise pH Measurements in the Alkaline Range.

ABSTRACT: The real-time monitoring of the intracellular pH in live cells with high precision represents an important methodological challenge. Although genetically encoded fluorescent indicators can be considered as a probe of choice for such measurements, they are hindered mostly by the inability to determine an absolute pH value and/or a narrow dynamic range of the signal, making them inefficient for recording the small pH changes that typically occur within cellular organelles. Here, we study the pH sensitivity of a green-fluorescence-protein (GFP)-based emitter (EGFP-Y145L/S205V) with the alkaline-shifted chromophore's pKa and demonstrate that, in the pH range of 7.5-9.0, its fluorescence lifetime changes by a factor of ~3.5 in a quasi-linear manner in mammalian cells. Considering the relatively

SUBMITTER: Simonyan TR 

PROVIDER: S-EPMC9658282 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature