title: Conformation of poly-L-glutamate is independent of ionic strength.
abstract: CD and UV resonance Raman measurements surprisingly find that the charge screening of even 2 M concentrations of NaCl and KCl does not alter the unfolded PPII and 2.5(1)-helix conformations of poly-L-glutamate. These salts appear to be excluded from the region between the side chain charges and the peptide backbone. Furthermore, no direct ion pairing occurs between these salts and the side chain carboxylates.
authors.affiliation: Department of Chemistry, University of Pittsburgh, PA 15260, USA.
authors.forename: Kan
authors.initials: K
authors.lastname: Xiong
authors.forename: Lu
authors.initials: L
authors.lastname: Ma
authors.forename: Sanford A
authors.initials: SA
authors.lastname: Asher
mesh_terms: D002942:Circular Dichroism; D008958:Models, Molecular; D009994:Osmolar Concentration; D011099:Polyglutamic Acid / Q000737:chemistry*; D011189:Potassium Chloride / Q000737:chemistry; D017433:Protein Structure, Secondary; D012965:Sodium Chloride / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: D011099:Polyglutamic Acid; D012965:Sodium Chloride; D011189:Potassium Chloride