In a series of neutron spin-echo experiments (NSE) on the proteins alcohol dehydrogenase (ADH) and phosphoglycerate kinase (PGK) large scale large amplitude domain motions with functional relevance have been observed. Our NSE experiments covered momentum transfer values up to 0.2Å-1. For larger Q-value the mixture of coherent and incoherent signal contributions with amplitude factors 1 and -1/3 respectively makes the NSE experiment tedious. The extension of the accessed Q range by the here proposed TOF experiment on PGK will explore how the inferred model extends from the low Q into the high(er)-Q behavior, relating large scale domain motions to more local fluctuations observed by TOF.