Isolation of bacterial luminescence reaction inhibitor from Photobacterium sp. cells

: The factor having a strong inhibitory effect on bacterial luminescence was isolated from the luminous bacteria species Photobacterium sp. The inhibitor purified by gel filtration on the biogel and by DEAE chromatography was homogenous (single bound during electrophoresis in polyacrylamide gel), it reacted with coomassie brilliant blue and gave a positive Lowry reaction on protein. Molecular weight was about 30,000 as determined by SDS-polyacrylamide gel electrophoresis. The absorption spectrum was characterised by the maximum at 209 nm and unexpressed maximum in the region of 260 nm. It was shown that the inhibitor had an efficient inhibitory effect on both partially- and highly purified luciferase preparations from different species of luminous bacteria, but it produced no effect on the activity of specific NADH: FMN-oxidoreductase.