The kinetic behavior of the β£-chymotrypsincatalyzed hydrolysis of the two p-nitroanilide substrates succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (Suc-Ala-Ala-Pro-Phe-pNA) and benzoyl-L-Tyr-p-nitroanilide (Bz-Tyr-pNA) was modeled and simulated for two different systems, namely for an aqueous solut
Quantum chemical modeling of enzymatic reactions: The case of histone lysine methyltransferase
β Scribed by Polina Georgieva; Fahmi Himo
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 725 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0192-8651
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β¦ Synopsis
Abstract
Quantum chemical cluster models of enzyme active sites are today an important and powerful tool in the study of various aspects of enzymatic reactivity. This methodology has been applied to a wide spectrum of reactions and many important mechanistic problems have been solved. Herein, we report a systematic study of the reaction mechanism of the histone lysine methyltransferase (HKMT) SET7/9 enzyme, which catalyzes the methylation of the Nβterminal histone tail of the chromatin structure. In this study, HKMT SET7/9 serves as a representative case to examine the modeling approach for the important class of methyl transfer enzymes. Active site models of different sizes are used to evaluate the methodology. In particular, the dependence of the calculated energies on the model size, the influence of the dielectric medium, and the particular choice of the dielectric constant are discussed. In addition, we examine the validity of some technical aspects, such as geometry optimization in solvent or with a large basis set, and the use of different density functional methods. Β© 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
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