Supplement Material

Temperature-dependent linear IR spectra of the CH deformation modes and their second derivatives of dEP and PdEA, the results of the normal mode analysis of dEP in water, diagonal slices of the 2D-IR spectra of PdEA, the scheme for the distorted 2D-IR spectra, confirmation of the CG transition in the simulations via evolution of the radius of gyration, hydrophobic contacts between the side chains that drive the CG transition, radial distribution functions between the methyl carbon atoms in side chains of PdEA, the obtained lj parameters by vibrational Stark shift method, the simulations of the linear- and 2D-IR spectra of dEP and PdEA, angle-resolved radial distribution functions at the carbonyl group, the number of hydrogen bonded water molecules around the carbonyl groups, the 2D time correlation plots between the hydration water molecules OO(water)H and the dihedral carbon angles i, and the obtained fitting parameters of the correlation functions of the dihedral angles of the backbone and water reorientations.