Quantum chemical studies of biochemical reaction mechanisms
Title: Quantum chemical studies of biochemical reaction mechanisms
SNIC Project: SNIC 2013/1-322
Project Type: SNAC Medium
Principal Investigator: Per Siegbahn <ps@organ.su.se>
Affiliation: Stockholm University
Duration: 2014-01-01 – 2015-01-01
Classification: 10407


This application concerns computer resources for studying mechanisms of redox active enzymes. Most previous studies have been performed on the Ferlin cluster at PDC, which is still active going. Using hybrid density functional theory and active site models of 100-400 atoms,  potential energy surfaces for different mechanisms are calculated. The computed results are compared to experimental reaction rates and other observations. There have been two major projects the past decade. The first one is water oxidation in photosystem II, for which results superior to experiments for both structures and mechanisms have ben obtained. The second one is oxygen reduction and proton pumping in cytochrome c oxidase in the respiratory chain. During recent years a mechanism has been obtained, which so far is the only one that stands all experimental observations. Other examples of redox mechanisms are also described. It is of utmost importance that these projects, which are at the top of similar projects in the world, continues to be substantially supported by computer funding.