NMR, Raman spectroscopy and ab initio quantum-chemical calculations have been employed to investigate the role of the hydration water in the inverse temperature transition of elastin-derived biopolymers represented by poly(Gly-Val-Gly-Val-Pro) and poly(Ala-Val-Gly-Val-Pro). Temperature and concentration dependences of the Raman spectra measured for water solutions of polymers and of a low-molecular-weight model have been correlated with the vibrational frequencies calculated at the DFT (B3LYP) and MP2 levels for the peptide segment surrounded by a growing number of water molecules. The results indicate strong hydration before the transition that, in addition to water hydrogen-bonded to amide groups, includes hydrophobic hydration of non-polar groups by a dynamic cluster of several water molecules. According to 1H longitudinal and transverse relaxation of HOD signals in D2O solutions, the number of water molecules motionally correlated with the polymer is about 4 per one amino acid residue.