ESR study of interfacial hydration layers of polypeptides in water-filled nanochannels and in vitrified bulk solvents.

ABSTRACT: There is considerable evidence for the essential role of surface water in protein function and structure. However, it is unclear to what extent the hydration water and protein are coupled and interact with each other. Here, we show by ESR experiments (cw, DEER, ESEEM, and ESE techniques) with spin-labeling and nanoconfinement techniques that the vitrified hydration layers can be evidently recognized in the ESR spectra, providing nanoscale understanding for the biological interfacial water. Two peptides of different secondary structures and lengths are studied in vitrified bulk solvents and in water-filled nanochannels of different pore diameter (6.1~7.6 nm). The existence of surface hydration and bulk shells are demonstrated. Water in the immediate vicinity of the nitroxide label (within t

SUBMITTER: Lai YC 

PROVIDER: S-EPMC3695931 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature