Separation of a blue fluorescence protein from bacterial luciferase

Luciferase preparations from two species of marine bioluminescent bacteria, Photobacterium phosphoreum and Photobacterium fischeri , are shown to contain a low molecular weight protein, containing a blue fluorescence chromophore having an emission maximum in the 470 nm region. A procedure for separating the luciferase and purifying this protein is described. On disc gel electrophoresis the bulk of the protein is observed to migrate along with the blue fluorescence.