Theoretical studies on the inactivation mechanism of gamma-aminobutyric acid aminotransferase


Durak A. T., GOKCAN H., KONUKLAR F. A. S.

ORGANIC & BIOMOLECULAR CHEMISTRY, cilt.9, sa.14, ss.5162-5171, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 9 Sayı: 14
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1039/c1ob05146f
  • Dergi Adı: ORGANIC & BIOMOLECULAR CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.5162-5171
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

The inactivation mechanism of g-aminobutyric acid aminotransferase (GABA-AT) in the presence of gamma-vinyl-aminobutyric acid, an anti-epilepsy drug, has been studied by means of theoretical calculations. Density functional theory methods have been applied to compare the three experimentally proposed inactivation mechanisms (Silverman et al., J. Biol. Chem., 2004, 279, 363). All the calculations were performed at the B3LYP/6-31+G(d,p) level of theory. Single point solvent calculations were carried out in water, by means of an integral equation formalism-polarizable continuum model (IEFPCM) at the B3LYP/6-31+G(d,p) level of theory. The present calculations provide an insight into the mechanistic preferences of the inactivation reaction of GABA-AT. The results also allow us to elucidate the key factors behind the mechanistic preferences. The computations also confirm the importance of explicit water molecules around the reacting center in the proton transfer steps.