title: Color tuning in photofunctional proteins.
abstract: Depending on protein environment, a single photofunctional chromophore shows a wide variation of photoabsorption/emission energies. This photobiological phenomenon, known as color tuning, is observed in human visual cone pigments, firefly luciferase, and red fluorescent protein. We investigate the origin of color tuning by quantum chemical calculations on the excited states: symmetry-adapted cluster-configuration interaction (SAC-CI) method for excited states and a combined quantum mechanical (QM)/molecular mechanical (MM) method for protein environments. This Minireview summarizes our theoretical studies on the above three systems and explains a common feature of their color-tuning mechanisms. It also discuss the possibility of artificial color tuning toward a rational design of photoabsorption/emission properties.
authors: Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan. hasegawa@fukui.kyoto-u.ac.jp
authors: Jun-ya
authors: JY
authors: Hasegawa
authors: Kazuhiro J
authors: KJ
authors: Fujimoto
authors: Hiroshi
authors: H
authors: Nakatsuji
mesh_terms: D003116:Color; D006801:Humans; D049409:Luciferases, Firefly / Q000737:chemistry*; D008164:Luminescent Proteins / Q000737:chemistry*; D011789:Quantum Theory; D012168:Retinal Pigments / Q000737:chemistry*; D055672:Static Electricity; D000097573:Red Fluorescent Protein
chemical_list: D049409:Luciferases, Firefly; D008164:Luminescent Proteins; D012168:Retinal Pigments; D000097573:Red Fluorescent Protein