Document Type

Article

Publication Date

1-26-2008

Abstract

β-Peptides made from L-aspartic acid monomers form a new class of β3-peptides. Here we report the first three-dimensional NMR solution structure of a β3-hexapeptide (1) from L-aspartic acid monomers in 2,2,2-trifluoroethanol (TFE). We show that 1 forms a right-handed 14-helical structure in TFE. α-peptides from naturally occurring L-amino acids adopt a right-handed α-helix whereas β3-peptides formed from β3-amino acids derived from naturally occurring L-amino acids form left-handed 14-helices. The right-handed 14-helical conformation of 1 is a better mimic of α-peptide conformations. Using the NMR structure of 1 in TFE, we further study the conformation of 1 in water, as well as two similar β3-peptides (2 and 3) in water and TFE by molecular dynamics (MD) simulations. NMR and MD results suggest loss of secondary structure of 1 in water and show that it forms a fully extended structure. 2 and 3 contain residues with oppositely charged side chains that engage in salt-bridge interactions and dramatically stabilize the 14-helical conformation in aqueous media.

Comments

NOTICE: this is the author’s version of a work that was accepted for publication in Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, volume 1784, issue 4, in 2008. DOI: 10.1016/j.bbapap.2008.01.009

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Copyright

Elsevier

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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