Details

Autor(en) / Beteiligte

• Baba, Takeshi
• Matsui, Toru
• Kamiya, Katsumasa
• Nakano, Masayoshi
• Shigeta, Yasuteru

Titel

A density functional study on the pKa of small polyprotic molecules

Ist Teil von

• International journal of quantum chemistry, 2014-09, Vol.114 (17), p.1128-1134

Ort / Verlag

Hoboken: Blackwell Publishing Ltd

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The pKa values of several biologically important small molecules in aqueous solution, such as salicylic acid, histamine, and dopamine, were determined by density functional theory combined with the polarizable continuum model, which has been proposed for predicting pKa values of nucleic acids and proteins. These molecules have plural protonation sites and the inherent pKa determines which protons exist at a specific pH. Taking into account the ensemble average, and that the order of the deprotonation steps is specific among several possible pathways, it emerged that the calculated pKa values mostly reproduced the experimental ones within an error of ± 1.0 pKa units. © 2014 Wiley Periodicals, Inc. The acid dissociation constant and its logarithm (pKa) are often used to specify the position of protons in biomolecules. A novel scheme to compute pKa values based on quantum chemical calculations combined with a polarizable continuum model is applied to several biologically important small molecules in aqueous solution such as salicylic acid, histamine, and dopamine. These molecules have plural protonation sites whose inherent pKa determines which protons exist at a specific pH.