title: Hydration dynamics at fluorinated protein surfaces.
abstract: Water-protein interactions dictate many processes crucial to protein function including folding, dynamics, interactions with other biomolecules, and enzymatic catalysis. Here we examine the effect of surface fluorination on water-protein interactions. Modification of designed coiled-coil proteins by incorporation of 5,5,5-trifluoroleucine or (4S)-2-amino-4-methylhexanoic acid enables systematic examination of the effects of side-chain volume and fluorination on solvation dynamics. Using ultrafast fluorescence spectroscopy, we find that fluorinated side chains exert electrostatic drag on neighboring water molecules, slowing water motion at the protein surface.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Oh-Hoon
authors.initials: OH
authors.lastname: Kwon
authors.forename: Tae Hyeon
authors.initials: TH
authors.lastname: Yoo
authors.forename: Christina M
authors.initials: CM
authors.lastname: Othon
authors.forename: James A
authors.initials: JA
authors.lastname: Van Deventer
authors.forename: David A
authors.initials: DA
authors.lastname: Tirrell
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Zewail
mesh_terms: D000595:Amino Acid Sequence; D005461:Fluorine / Q000737:chemistry*; D054879:Halogenation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D011506:Proteins; D014867:Water; D005461:Fluorine