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Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Water-Soluble Polypeptides with Elongated, Charged Side Chains Adopt Ultra-Stable Helical Conformations
Yanfeng Zhang1, Hua Lu, Yao Lin
1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
None:
Water-soluble polypeptides adopting α-helical conformations with unprecedented high helicities were obtained by elongating the charge-containing side chains of the constituent amino acids to allow the terminal charges to be situated distally from the peptide backbone. Poly(γ-(4-aminoethylthiopropoxyl)-benzyl-(L)-glutamate) (PAOBLG-AET) with a charge-peptide backbone distance of 17 σ-bonds exhibited a remarkably high helical content (81%) at a degree of polymerization as low as 10. The helical conformations of these short polypeptides were very stable against various harsh, protein-denaturing conditions, such as extreme pH, high temperature, and high salt or urea concentrations.
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