首页 | 本学科首页   官方微博 | 高级检索  
     


Protein environmental effects on iron‐sulfur clusters: A set of rules for constructing computational models for inner and outer coordination spheres
Authors:Travis V. Harris  Robert K. Szilagyi
Affiliation:NAI Astrobiology Biogeocatalysis Research Center, Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana
Abstract:The structural properties and reactivity of iron‐sulfur proteins are greatly affected by interactions between the prosthetic groups and the surrounding amino acid residues. Thus, quantum chemical investigations of the structure and properties of protein‐bound iron‐sulfur clusters can be severely limited by truncation of computational models. The aim of this study was to identify, a priori, significant interactions that must be included in a quantum chemical model. Using the [2Fe‐2S] accessory cluster of the FeFe‐hydrogenase as a demonstrative example with rich electronic structural features, the electrostatic and covalent effects of the surrounding side chains, charged groups, and backbone moieties were systematically mapped through density functional theoretical calculations. Electron affinities, spin density differences, and delocalization indexes from the quantum theory of atoms in molecules were used to evaluate the importance of each interaction. Case studies for hydrogen bonding and charged side‐chain interactions were used to develop selection rules regarding the significance of a given protein environmental effect. A set of general rules is proposed for constructing quantum chemical models for iron‐sulfur active sites that capture all significant interactions from the protein environment. This methodology was applied to our previously used models in galactose oxidase and the 6Fe‐cluster of FeFe‐hydrogenase. © 2016 Wiley Periodicals, Inc.
Keywords:iron‐sulfur clusters  inner and outer coordination spheres  bond covalency  ionic interactions  hydrogen bonding  protein environment
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号