We have transformed the Scott's model of protein Hamiltonian to metastable form, by means of double coherent unitary transformation. It turned out that in metastable Hamiltonian the number of quasi particles is not conserved due to the forming of pairs of excitations. The energies of pairs are found and their population is quoted. It is interesting that elementary excitations of metastable state behave similarly as excitations of molecular vibration field as well as excitations of electromagnetic field