title: Studies to reveal the nature of interactions between catalase and curcumin using computational methods and optical techniques.
abstract: Curcumin is an important antioxidant compound, and is widely reported as an effective component for reducing complications of many diseases. However, the detailed mechanisms of its activity remain poorly understood. We found that curcumin can significantly increase catalase activity of BLC (bovine liver catalase). The mechanism of curcumin action was investigated using a computational method. We suggested that curcumin may activate BLC by modifying the bottleneck of its narrow channel. The molecular dynamic simulation data showed that placing curcumin on the structure of enzyme can increase the size of the bottleneck in the narrow channel of BLC, and readily allow the access of substrate to the active site. Because of the increase of the distance between amino acids of the bottleneck in the presence of curcumin, the entrance space of substrate increased from 250Å3to 440Å3. In addition, the increase in emission of intrinsic fluorescence of BLC in presence of curcumin demonstrated changes in tertiary structure of catalase, and possibility of less quenching. We also used circular dichroism (CD) spectropolarimetry to determine how curcumin may alter the enzyme secondary structure. Catalase spectra in the presence of various concentrations of curcumin showed an increase in the amount of α-helix content.
authors.affiliation: Department of Chemistry, Shahid Beheshti University, Tehran, Iran; Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
authors.forename: Fayezeh
authors.initials: F
authors.lastname: Mofidi Najjar
authors.affiliation: Computational Chemistry Laboratory, Department of Organic and Biochemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Rahim
authors.initials: R
authors.lastname: Ghadari
authors.affiliation: Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Yousefi
authors.affiliation: Department of Chemistry, Shahid Beheshti University, Tehran, Iran.
authors.forename: Naser
authors.initials: N
authors.lastname: Safari
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Sheikhhasani
authors.affiliation: Departments of Ophthalmology and Visual Sciences, and Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; Center of Excellence in Biothermodynamics, University of Tehran, Tehran, Iran. Electronic address: moosavi@ut.ac.ir.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Moosavi-Movahedi
mesh_terms: D000818:Animals; D002374:Catalase / Q000737:chemistry* / Q000378:metabolism*; D020134:Catalytic Domain; D002417:Cattle; D003474:Curcumin / Q000378:metabolism*; D008958:Models, Molecular; D055620:Optical Phenomena; D011485:Protein Binding
chemical_list: D002374:Catalase; D003474:Curcumin
keywords: Catalase activity; Curcumin; Main channel