Computer modelling of enzyme reactions

G. Náray-Szabó, Imre Berente

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We give an overview on modern methods and atomistic models for the computation of enzyme mechanisms. It has to be stressed that models and methods must be at the same level of sophistication. If essential components (H-bonding side chains, metal ion, cofactor, etc.) of the active site are absent from the model, even the largest basis set may provide false results. On the other hand, the largest model with dozens of explicit atoms may lead to artefacts if the accuracy of the computational method (minimal basis set ab initio, semi-empirical or molecular force field) is unsatisfactory. Enzyme reactions are especially adequate for the application of an embedding scheme. While the active site should be treated by a high-level quantum mechanical method, distant protein atoms may be considered at a lower level of accuracy, e.g. as fixed point charges. The biophase is best treated by the DelPhi method, which is based on the solution of the linearised Poisson-Boltzmann equation and considers important counter-ion shielding effects on charged surface side chains. An integrated version of the embedding scheme is the combination of quantum mechanical and molecular mechanical methods (QM/MM) allowing treating all protein atoms in a calculation, however, at different levels of sophistication. Here we may have problems for atoms at the boundary, for which we present our approach offering a natural partition of the active site and protein core by applying strictly localised molecular orbitals. Two enzyme mechanisms, those of HIV integrase and xylose isomerase will be discussed in more detail in order to illustrate the principles outlined above.

Original languageEnglish
Pages (from-to)637-644
Number of pages8
JournalJournal of Molecular Structure: THEOCHEM
Volume666-667
DOIs
Publication statusPublished - Dec 29 2003

Fingerprint

enzymes
Enzymes
Atoms
proteins
Proteins
xylose isomerase
embedding
atoms
Delphi method (forecasting)
Catalytic Domain
HIV Integrase
xylose
human immunodeficiency virus
Xylose
Radiation counters
Boltzmann equation
Molecular orbitals
Computational methods
Shielding
Ions

Keywords

  • Enzyme
  • Molecular mechanical methods
  • Quantum mechanical methods

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Computational Theory and Mathematics
  • Atomic and Molecular Physics, and Optics

Cite this

Computer modelling of enzyme reactions. / Náray-Szabó, G.; Berente, Imre.

In: Journal of Molecular Structure: THEOCHEM, Vol. 666-667, 29.12.2003, p. 637-644.

Research output: Contribution to journalArticle

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