A turquoise fluorescence lifetime-based biosensor for quantitative imaging of intracellular calcium.

ABSTRACT: The most successful genetically encoded calcium indicators (GECIs) employ an intensity or ratiometric readout. Despite a large calcium-dependent change in fluorescence intensity, the quantification of calcium concentrations with GECIs is problematic, which is further complicated by the sensitivity of all GECIs to changes in the pH in the biological range. Here, we report on a sensing strategy in which a conformational change directly modifies the fluorescence quantum yield and fluorescence lifetime of a circular permutated turquoise fluorescent protein. The fluorescence lifetime is an absolute parameter that enables straightforward quantification, eliminating intensity-related artifacts. An engineering strategy that optimizes lifetime contrast led to a biosensor that shows a 3-fold change

SUBMITTER: van der Linden FH 

PROVIDER: S-EPMC8660884 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature