Fragment Molecular Orbital Study on Electron Tunneling in Protein
Hirotaka Kitoh-Nishioka1 , Koji Ando2
1Japan Science and Technology Agency (JST) PRESTO and Center for Computational Sciences, University of Tsukuba, Ibaraki 305-8517, Japan
2Department of Information and Sciences, Tokyo Woman’s Christian University, Suginami-ku, Tokyo 167-8585, Japan
We have developed a computational scheme [1] to efficiently analyze biological electron transfer (ET) reactions by making use of fragment molecular orbital (FMO) method [2]. Biological ET usually takes place via the long-distance single-electron tunneling between redox centers embedded in protein, where the tunneling electron uses the electronic structures provided by protein environment as its virtual intermediate states through the super-exchange mechanism. Our scheme [1] first calculates the wave function of the tunneling electron with FMO-linear combination of MOs of the fragment (FMO-LCMO) method [3], and then uses a tunneling current method [4] with the resultant wave function to obtain the super-exchange electronic coupling and the dominant electron tunneling pathways in protein. In this talk, we present the applications of our scheme to several model ET systems, including long-distance hole transfer from oxidized ruthenium Ru(III) complex to reduced type I copper center CU(I) through polyglycine linkers.
H. K.-N. acknowledges support from JST, PRESTO Grant Number JPMJPR17G4.
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