Computational studies of orange carotenoid protein (OCP) families

Computational studies of the orange carotenoid protein (OCP) families, combining comparative modeling and molecular dynamics simulation

Cyanobacteria photoprotective mechanisms include the non-photochemical quenching (NPQ) of the phycobilisome fluorescence.

  • Carotenoid binding proteins (CBP) interact with the phycobilisome and inhibit the fluorescence in ways of heat dissipation.

  • Diversity of these CBP includes the orange carotenoid protein (OCP). Upon photoexcitation, OCP converts from the orange state (OCPO) to the red state (OCPR).

  • We are developing homology models of the red state of GlOCP1 and its mutant, OCP from Gloeocapsa sp. PCC 7513, using the x-ray crystal structure of SyOCP1.
  • 3D structures of SyOCP1R and GlOCP1R (left), GlOCP1R and GlOCP1R V40I (right)

Future Direction

  • Calculation of absorption spectra based on major clusters of GlOCP1R and GlOCP1R V40I, and comparison with the sample mean and experimental result
  • Clustering the ligand to analyze the structure difference according to the calculated previous absorption spectra
  • Molecular dynamics simulation while lowering the temperature to find the proper protein structure