title: Impact of Strand Number on Parallel β-Sheet Stability.
abstract: We have examined whether parallel β-sheet secondary structure becomes more stable as the number of β-strands increases, via comparisons among peptides designed to adopt two- or three-stranded parallel β-sheet conformations in aqueous solution. Our three-strand design is the first experimental model of a triple-stranded parallel β-sheet. Analysis of the designed peptides by nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopy supports the hypothesis that increasing the number of β-strands, from two to three, increases the stability of the parallel β-sheet. We present the first experimental evidence for cooperativity in the folding of a triple-stranded parallel β-sheet, and we show how minimal model systems may enable experimental documentation of characteristic properties, such as CD spectra, of parallel β-sheets.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706 (USA).
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Kung
authors.affiliation: National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, 433 Babcock Dr., Madison, WI 53706 (USA).
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cornilescu
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706 (USA). gellman@chem.wisc.edu.
authors.forename: Samuel H
authors.initials: SH
authors.lastname: Gellman
mesh_terms: D002942:Circular Dichroism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation
keywords: NMR spectroscopy; circular dichroism; cooperativity; parallel β-sheet; protein design