Studying Light Production in the Sea at the Molecular Level
by Patrick H. Donnan
Dinoflagellate bioluminescence is triggered upon physical agitation of the organism, and dinoflagellates utilize special organelles which house both luciferase and luciferin to make this happen. These organelles, called scintillons, are biochemically configured such that shaking the organisms causes the acidity in the scintillon to increase. The increase in acidity, which is the same as decreasing the pH, turns luciferase active. In order to study the process by which this happens, we have employed a computational technique called molecular dynamics (MD). MD allows us to simulate biomolecules, such as enzymes, and watch how their behavior changes over time. MD simulations use structures determined by methods such as X-ray crystallography as starting points for computer-based investigations. While for many biomolecules, numerous structures have been obtained by X-ray crystallography, only one exists for dinoflagellate luciferase. MD provides a tool for filling in the gaps and determining biomolecular structures, with the added benefit of being able to observe the structure in motion.
Acknowledgement: This work is supported by the National Sciences Foundation and Alabama EPSCoR and was done in the lab of Prof. Steve Mansoorabadi in the department of Chemistry and Biochemistry, Auburn University.