Purification and characterization of a novel thermostable luciferase from Benthosema pterotum

•A novel thermostable luciferase from Benthosema pterotum (BP) was purified.•The molecular mass of novel enzyme is about 27 kDa and its Km value is 0.4 ± 0.01 μM.•BP luciferase showed maximum intensity of emitted light at 40 °C, pH 9 and 30 mM magnesium.•BP luciferase is a thermostable enzyme and it shows a high activity at extreme pH values.•BP luciferases generated blue light with a maximum emission wavelength at 475 nm.

A novel luciferase from Benthosema pterotum, collected from Port of Jask, close to Persian Gulf, was purified for the first time, using Q-Sepharose anion exchange chromatography. The molecular mass of the novel enzyme, measured by SDS–PAGE technique, was about 27 kDa and its Km value is 0.4 μM; both values are similar to those of other coelenterazine luciferases. B. pterotum (BP) luciferase showed maximum intensity of emitted light at 40 °C, in 20 mM Tris buffer, pH 9 and 20 mM magnesium concentration. Experimental measurements indicated that BP luciferase is a relatively thermostable enzyme; furthermore it shows a high residual activity at extreme pH values. Its biological activity is strongly inhibited by 1 mM Cu2+, Zn2+ and Ni2+, while calcium and mainly magnesium ions strongly increase BP luciferase activity. The B. pterotum luciferase generated blue light with a maximum emission wavelength at 475 nm and showed some similarity with other luciferases, while other parameters appeared quite different, in this way, confirming that a novel protein has been purified.