Figure 8.

Sterically modified luciferins as orthogonal probes. (A) Divergent synthesis of luciferin analogs. Common benzothiazole intermediates were used to access an array of C4′- and C7′- modified luciferins. (B) Modeling studies suggested that C4′ and C7′ are prime targets for modification. These positions lie in close proximity to the Fluc backbone (PDB: 4G36). (C) Luciferin analogs exhibit varying levels of light output with Fluc. Analogs (100 μM) were incubated with Fluc (1 μg) and photon outputs were measured. Emission intensities are plotted as total photon flux values on a log scale. Adapted with permission from ref. 40. Copyright 2017 American Chemical Society.