Quadratic configuration interaction procedure with single and double electronic excitations (QCISD) has been used, for the first time, to calculate the electronic structure of the Compound I (CpdI), which represents a key intermediate in the catalytic cycle of Horseradish Peroxidase (HRP) enzyme. The QCISD method is applied to lowest quasi-isoenergetic doublet and quartet spin multiplicity and results compared with density functional theory (DFT/B3LYP) data. This investigation shows that, at present, QCISD is more accurate than DFT-based approach in discriminating between the two lowest magnetic states of CpdI complex in HRP enzyme. Such a result opens the possibility of theoretically addressing the reaction mechanism leading to CpdI complex in HRP using a correlated wavefunction based approach. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Compound I in HRP enzyme: Magnetic assessment by Quadratic Configuration Interaction calculations.
Palma A
2009
Abstract
Quadratic configuration interaction procedure with single and double electronic excitations (QCISD) has been used, for the first time, to calculate the electronic structure of the Compound I (CpdI), which represents a key intermediate in the catalytic cycle of Horseradish Peroxidase (HRP) enzyme. The QCISD method is applied to lowest quasi-isoenergetic doublet and quartet spin multiplicity and results compared with density functional theory (DFT/B3LYP) data. This investigation shows that, at present, QCISD is more accurate than DFT-based approach in discriminating between the two lowest magnetic states of CpdI complex in HRP enzyme. Such a result opens the possibility of theoretically addressing the reaction mechanism leading to CpdI complex in HRP using a correlated wavefunction based approach. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
