| Literature DB >> 11855285 |
Abstract
Quantum chemistry methods [RHF/UHF + MP4(FULL), DFT:B3LYP] with the 6-311+ +G**(p,d) basis set were used to elucidate the properties of six coordinated Mg2+ complexes with water, glutamic acid and ATP/GTP in singlet (S) and triplet (T) states. In the triplet state, the magnesium complex concentrates its spin density on a coordinated water molecule (inner or outer coordination shell). Within the molecule, a redox reaction occurs, and one of the hydrogen atoms is pushed out of the complex at a speed of approximately 125 m/s. In water solution, the energy of the triplet state is higher than that of the singlet state. In a mixed environment composed of water, amino acids and ATP/GTR, the energy of the magnesium complex in the triplet state is lower than that in the singlet state by 1.5-2.0 kcal/mol. A little difference in T and S states allows the Mg(2+)-ATP/GTP complex to switch easily between two reaction mechanisms.Entities:
Mesh:
Substances:
Year: 2002 PMID: 11855285
Source DB: PubMed Journal: Biofizika ISSN: 0006-3029