DSpace
 

DSpace at IIT Bombay >
IITB Publications >
Article >

Please use this identifier to cite or link to this item: http://dspace.library.iitb.ac.in/jspui/handle/10054/3817

Title: Electronic structure of a Rieske iron-sulfur complex and the calculation of its reduction potential
Authors: DATTA, SN
NEHRA, V
JHA, A
Keywords: quantum-chemical calculation
protein
chloroplast
Issue Date: 1999
Publisher: AMER CHEMICAL SOC
Citation: JOURNAL OF PHYSICAL CHEMISTRY B, 103(41), 8768-8772
Abstract: The electronic structure of a Rieske iron-sulfur complex of spinach chloroplast has been investigated by the CNDO/2 method. The crystallographic coordinates were obtained from the Protein Data Bank at Brookhaven National Laboratory. The protein chain was truncated in such a way that the entity Fe2S2 along with its four ligands was separated from the rest of the chain. The separated species retains the essential structural features of the Rieske iron-sulfur complex. It consists of the basic Fe2S2 unit, two histidine residues, and two cysteine residues such that each Fe atom is tetrahedrally coordinated. The orbital angular momenta of the iron atoms are found to be fully quenched. The HOMOs and the first few LUMOs are basically pi type orbitals of the Fe2S2 cluster with predominantly large contributions from the sulfur orbitals. The reduction potential calculated for the soluble Rieske iron-sulfur fragment in an aqueous solution at pH 7 is 0.370 V at 25 degrees C, which is in excellent agreement with the experimentally determined midpoint potential, 0.375 V. The calculated potential for the Rieske cluster in the condensed phase of thylakoid is 0.252 V, which agrees with the placement of the Rieske complex in the Z-scheme of photosynthesis in green plants.
URI: http://dx.doi.org/10.1021/jp991758b
http://dspace.library.iitb.ac.in/xmlui/handle/10054/3817
http://hdl.handle.net/10054/3817
ISSN: 1089-5647
Appears in Collections:Article

Files in This Item:

There are no files associated with this item.

View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback