Chromophore carbonyl twisting in fluorescent biosensors encodes direct readout of protein conformations with multicolor switching.

ABSTRACT: Fluorescent labeling of proteins is a powerful tool for probing structure-function relationships with many biosensing applications. Structure-based rules for systematically designing fluorescent biosensors require understanding ligand-mediated fluorescent response mechanisms which can be challenging to establish. We installed thiol-reactive derivatives of the naphthalene-based fluorophore Prodan into bacterial periplasmic glucose-binding proteins. Glucose binding elicited paired color exchanges in the excited and ground states of these conjugates. X-ray structures and mutagenesis studies established that glucose-mediated color switching arises from steric interactions that couple protein conformational changes to twisting of the Prodan carbonyl relative to its naphthalene plane. Mutations

SUBMITTER: Allert MJ 

PROVIDER: S-EPMC10439942 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature