Mikael P Johansson
Affiliation: University of Helsinki
- The spin distribution in low-spin iron porphyrinsMikael P Johansson
Department of Chemistry, P O Box 55 FIN 00014, University of Helsinki, Finland
J Am Chem Soc 124:11771-80. 2002..3 electrons. It seems that the degree to which alpha and beta spin dominate in different regions of the heme structure, as evidenced in these calculations, has not been previously observed...
- Spin and charge distribution in iron porphyrin models: a coupled cluster and density-functional studyMikael P Johansson
Department of Chemistry, P O Box 55 A I Virtanens Plats 1, FIN 00014 University of Helsinki, Finland
J Chem Phys 120:3229-36. 2004..Slight differences in the descriptions are noted and discussed...
- Interheme electron tunneling in cytochrome c oxidaseVille R I Kaila
Helsinki Bioenergetics Group, Structural Biology and Biophysics Programme, Institute of Biotechnology, University of Helsinki, PO Box 65, FI 00014 Helsinki, Finland
Proc Natl Acad Sci U S A 107:21470-5. 2010..We argue that this modification may be necessary at short donor/acceptor distances comparable to the donor/acceptor radii...
- The chemistry of the CuB site in cytochrome c oxidase and the importance of its unique His-Tyr bondVille R I Kaila
Helsinki Bioenergetics Group, Programme of Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
Biochim Biophys Acta 1787:221-33. 2009..The combined results provide an explanation for why the heme-copper oxidases need two pathways of proton uptake, and why the K-pathway is active only in the second half of the reaction cycle...
- Charge parameterization of the metal centers in cytochrome c oxidaseMikael P Johansson
Department of Chemistry, University of Helsinki, P O Box 55, FI 00014 Helsinki, Finland
J Comput Chem 29:753-67. 2008..Several relevant charge and ligand states are considered. Charges for two different force fields, CHARMM and AMBER, are presented...
- Ab initio, density functional theory, and semi-empirical calculationsMikael P Johansson
Department of Chemistry, University of Helsinki, Helsinki, Finland
Methods Mol Biol 924:3-27. 2013..We start by presenting ab initio methods, followed by a treatment of density functional theory (DFT) and some recent advances in semi-empirical methods. Treatment of excited states as well as basis sets are also presented...
- WAu12(CO)12?Mikael P Johansson
Laboratory for Instruction in Swedish, Department of Chemistry, University of Helsinki, P O Box 55, FI 00014 Helsinki, Finland
Chem Commun (Camb) 46:3762-4. 2010..The symmetry remains I(h) and the binding energy per carbonyl is about 100 kJ mol(-1) up to the last one...
- Autoxidation of conjugated linoleic acid methyl ester in the presence of alpha-tocopherol: the hydroperoxide pathwayTaina I Pajunen
Department of Chemistry, University of Helsinki, A I Virtasen Aukio 1, Helsinki, 00014, Finland
Lipids 43:599-610. 2008..As a result, a better understanding of the isomeric distribution of the product hydroperoxides was achieved and a modified mechanism that accounts for these calculations is presented...
- Change in electron and spin density upon electron transfer to haemMikael P Johansson
Department of Chemistry, P O Box 55 A I Virtanens Plats 1, University of Helsinki, FIN 00014, Helsinki, Finland
Biochim Biophys Acta 1553:183-7. 2002..The lost individuality of the electron added to the haem on reduction is another example of the importance of quantum mechanical effects in biological systems...
- Coupled-cluster and density functional theory studies of the electronic excitation spectra of trans-1,3-butadiene and trans-2-propeniminiumOlli Lehtonen
Department of Chemistry, University of Helsinki, POB 55 A I Virtanens plats 1, Helsinki FIN 00014, Finland
J Chem Phys 131:024301. 2009..The results also demonstrate that standard density functionals are not capable of providing excitation energies of sufficient accuracy for experimental assignments...
- Nanosecond electron tunneling between the hemes in cytochrome bo3Audrius Jasaitis
Laboratoire d Optique et Biosciences, Centre National de la Recherche Scientifique, Ecole Polytechnique, 91128 Palaiseau, France
Proc Natl Acad Sci U S A 104:20811-4. 2007..The properties of eT between the closely lying heme groups in the heme-copper oxidases are discussed in terms of the reorganization energy for the process, and two methods for assessing the rate of electron tunneling are presented...