Computational studies of dielectric permittivity effects on chemical shifts of alanine dipeptide

► A peptide model is used to study non-specific solvent effects on chemical shifts. ► Chemical shifts are highly sensitive to dielectric constant, ε, of the medium. ► The dependence can be approximated as an effect of the solvent reaction field. ► Small deviation of ε at the low-value region can induce large chemical shift changes. ► Averaged backbone chemical shifts suggest low effective ε for protein interior.