QCMEE study of the reductive half-reaction of glucose oxidase

✍ Scribed by Karl Jug; Heiko Gerwens

• Book ID: 102652918
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 697 KB
• Volume: 77
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(2000)77:1<71::aid-qua8>3.0.co;2-a

✦ Synopsis

A quantum-chemical model for electrostatic effects (QCMEE) in biomolecules is applied to the reductive half-reaction of glucose oxidase. The electrostatic influence of the enzyme on its active center is estimated. Six different states of protonation of the active center are compared by a hybrid method where the relative energies of the active center states are calculated ab initio and the relative energies of the electrostatic interaction between the active center and the rest enzyme are calculated by the quantum-chemical model. These model calculations comprise the total enzyme consisting of 8784 atoms. It is found that the double protonation of the histidine group His516 is greatly stabilized by the electrostatic interaction with the rest enzyme. This explains the experimental findings that His516 is essential for the function of the enzyme.