Ghaedizadeh_2016_Biochem.Eng.J_105_505

Renilla luciferase is a bioluminescent enzyme which is broadly implemented as cellular marker in many biology-related researches. In order to understand how the of enzyme is influenced by ionic liquids, we performed a combined experimental and molecular dynamics simulation study of Renilla luciferase in ionic liquids. Our results revealed a main tunnel in the structure of Renilla luciferase, and demonstrated that the conformational changes of the main tunnel are directly related to enzyme activity and the enzyme activity is decreased severely in the presence of [BMIM][BF4] and [BMIM][PF6]. While the main tunnel shows a screw in shape in the region near to active site in the presence of [BMIM][BF4], the entrance to the main tunnel is modulated by alanine 150 and isoleucine 265 in the presence of [BMIM][PF6]. The protein-ionic liquid interactions also have impact on the structure of enzyme, especially in [BMIM][PF6], where interactions of Renilla luciferase (with alpha/beta Fold) with fluorine anions causes a conformational collapse in the exposed alpha-helices. Based on the results, the structural distortions in Renilla luciferase in the presence of ionic liquids is started from the outer layer of the enzyme, a model which is called the alpha-shield collapse model