engleski

Hydrogen bond dynamics of histamine monocation in aqueous solution: how geometric arameters influence the hydrogen bond strength

Chemometric statistical approaches involving multiple linear regression (MLR) and principal component analysis (PCA) were employed on a set of 42 distinct snapshot structures of the physiological histamine monocation in aqueous solution along the Car-Parrinello molecular dynamics trajectory, in order to obtain a better insight into the relationship between the geometry parameters of the system and the resulting νNH stretching frequencies. A simple 2D linear regression of νNH with Namino···Owater distances gave a very poor correlation (R2 = 0.42), but both MLR and PCA with the inclusion of four directly bonded water molecules offered a notably predictive model that is even able to distinguish two classes of structures based on the Cl- counterion position. Taking into account waters from the first, second and third solvation shells, sequentially diminished the overall predictive ability of the model, yet increased the number of useful predictors that, in the largest model with 51 solvent molecules, all correspond to bulk water, implying that both chemometric methods are consistent in suggesting that fundamental histamine N–H stretching vibrations are very complex in nature and strongly coupled to the fluctuating environment.

hydrogen bond ; hystamine monocation ; multiple linear regresion ; principal component analysis

nije evidentirano