Published August 30, 2023 | Version v1

Illuminating the mechanism and allosteric behavior of NanoLuc luciferase

Description

NanoLuc, a superior β-barrel fold luciferase, was engineered 10 years ago but the nature of its catalysis
remains puzzling. Here experimental and computational techniques were combined, revealing that
imidazopyrazinone luciferins bind to an intra-barrel catalytic site but also to an allosteric site shaped on
the enzyme surface. Binding to the allosteric site prevents simultaneous binding to the catalytic site, and
vice versa, through concerted conformational changes. We demonstrate that restructuration of the
allosteric site can boost the luminescent reaction in the remote active site. Mechanistically, an intra-barrel
arginine coordinates the imidazopyrazinone component of luciferin which then react with O 2 via a radical
charge-transfer mechanism, and it also protonates the resulting excited amide product to form a light-
emitting neutral species. Concomitantly, an aspartate, supported by two tyrosines, is fine-tuning the blue
color emitter to secure a high emission intensity. This information is critical to engineering the next-
generation of ultrasensitive bioluminescent reporters.

Files

MechanismAllosteryNanoLuc.zip

Files (7.1 GB)

Name Size
md5:d56f532d6c29773770252e3e280093bd
7.1 GB Preview Download

Additional details

Funding

European Commission
ADDIT-CE - Alzheimer's Disease Diagnostics Innovation and Translation to Clinical Practice in Central Europe 101087124
European Commission
SinFonia - Synthetic biology-guided engineering of Pseudomonas putida for biofluorination 814418
European Commission
CETOCOEN Excellence - CETOCOEN Excellence 857560