Migration and chemical reaction of H+ in protonated β-galactose

Abstract

Equilibrium structures for a proton on β-D-galactose and transition states for proton hopping are computed. Also, Ab Initio Molecular Dynamics (AIMD) simulations are carried out. All calculations used B3LYP potentials with dispersion. At 40 K, proton hopping between sites is of near microsecond timescale. At 300 K, the proton migrates across the sugar on a sub-picosecond timescale. At 500 K, the proton reacts with the sugar to produce H₂O. Implications for sugar chemistry are discussed.