The bioluminescence activity of Gluc is sensitive to its redox environment.
A, Amino-acid sequence of Gluc showing two homogenous subdomains and the disulfides. Three of the five disulfide bonds have been characterized by mass spectrometry (unpublished data). The 17-residue signal peptide is underlined. B, The bioluminescent activity of Gluc is DTT concentration dependent. The purified Gluc protein was incubated with different concentrations of DTT for 6 hrs at room temperature. The activity was represented as a percentage of the original Gluc activity without DTT. The bioluminescence decreases dramatically with the treatment of 0.1–1 mM DTT.