Cell viability is dominated by quantum effects
Quantum tunneling is a phenomenon in which small quantum particles pass through a reaction energy barrier, as if they were passing through a tunnel opened in the barrier. In this study, we analyzed the involvement of the quantum tunneling effect in enzymatic chemical reactions involving hydrolysis in vitro, by monitoring the kinetic isotope effects due to hydrogen isotopes and their temperature dependence as indicators. The results demonstrated that the quantum tunneling effect is involved in deacetylation, DNA cleavage, and protein cleavage reactions. These related reactions were also examined in terms of their effects on cells, which revealed that the quantum effect is even involved in cell survival, including the almost complete inhibition of DNA homologous recombinational repair. One-Sentence SummaryDue to quantum effects in numerous enzymatic reactions mediated by hydrolysis, heavy water significantly impacts biological outcomes in cells.