Abstract
Helices are the most extensively studied secondary structures formed by β-peptide foldamers. Among the five known β-peptide helices, the 12-helix is particularly interesting because the internal hydrogen bond orientation and macrodipole are analogous to those of α-peptide helices (α-helix and 310-helix). The β-peptide 12-helix is defined by i, i+3 C - O•••H-N backbone hydrogen bonds and promoted by β-residues with a five-membered ring constraint. The 12-helical scaffold has been used to generate β-peptides with specific biological functions, for which diverse side chains must be properly placed along the backbone and, upon folding, properly arranged in space. Only two crystal structures of 12-helical β-peptides have previously been reported, both for homooligomers of trans-2-aminocyclopentanecarboxylic acid (ACPC). Here we report five additional crystal structures of 12-helical β-peptides, all containing residues that bear side chains. Four of the crystallized β-peptides include trans-4,4-dimethyl-2-aminocyclopentanecarboxylic acid (dm-ACPC) residues, and the fifth contains a β3-hPhe residue. These five β-peptides adopt fully folded 12-helical conformations in the solid state. The new crystal structures, along with previously reported data, allow a detailed characterization of the 12-helical conformation; average backbone torsion angles of β-residues and helical parameters are derived. These structural parameters are found to be similar to those for i, i+3 C = O⋯H-N hydrogen-bonded helices formed by other peptide backbones generated from α- and/or β-amino acids. The similarity between the conformational behavior of dm-ACPC and ACPC is consistent with previous NMR-based conclusions that 4,4-disubstituted ACPC derivatives are compatible with 12-helical folding. In addition, our data show how a β3-residue is accommodated in the 12-helix, thus enhancing understanding of the diverse conformational behavior of this flexible class of β-amino acids.
| Original language | English |
|---|---|
| Pages (from-to) | 13879-13885 |
| Number of pages | 7 |
| Journal | Journal of the American Chemical Society |
| Volume | 132 |
| Issue number | 39 |
| DOIs | |
| Publication status | Published - 2010 Oct 6 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry
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Crystallographic characterization of 12-helical secondary structure in β-peptides containing side chain groups. / Choi, Soo Hyuk; Guzei, Ilia A.; Spencer, Lara C.; Gellman, Samuel H.
In: Journal of the American Chemical Society, Vol. 132, No. 39, 06.10.2010, p. 13879-13885.Research output: Contribution to journal › Article
TY - JOUR
T1 - Crystallographic characterization of 12-helical secondary structure in β-peptides containing side chain groups
AU - Choi, Soo Hyuk
AU - Guzei, Ilia A.
AU - Spencer, Lara C.
AU - Gellman, Samuel H.
PY - 2010/10/6
Y1 - 2010/10/6
N2 - Helices are the most extensively studied secondary structures formed by β-peptide foldamers. Among the five known β-peptide helices, the 12-helix is particularly interesting because the internal hydrogen bond orientation and macrodipole are analogous to those of α-peptide helices (α-helix and 310-helix). The β-peptide 12-helix is defined by i, i+3 C - O•••H-N backbone hydrogen bonds and promoted by β-residues with a five-membered ring constraint. The 12-helical scaffold has been used to generate β-peptides with specific biological functions, for which diverse side chains must be properly placed along the backbone and, upon folding, properly arranged in space. Only two crystal structures of 12-helical β-peptides have previously been reported, both for homooligomers of trans-2-aminocyclopentanecarboxylic acid (ACPC). Here we report five additional crystal structures of 12-helical β-peptides, all containing residues that bear side chains. Four of the crystallized β-peptides include trans-4,4-dimethyl-2-aminocyclopentanecarboxylic acid (dm-ACPC) residues, and the fifth contains a β3-hPhe residue. These five β-peptides adopt fully folded 12-helical conformations in the solid state. The new crystal structures, along with previously reported data, allow a detailed characterization of the 12-helical conformation; average backbone torsion angles of β-residues and helical parameters are derived. These structural parameters are found to be similar to those for i, i+3 C = O⋯H-N hydrogen-bonded helices formed by other peptide backbones generated from α- and/or β-amino acids. The similarity between the conformational behavior of dm-ACPC and ACPC is consistent with previous NMR-based conclusions that 4,4-disubstituted ACPC derivatives are compatible with 12-helical folding. In addition, our data show how a β3-residue is accommodated in the 12-helix, thus enhancing understanding of the diverse conformational behavior of this flexible class of β-amino acids.
AB - Helices are the most extensively studied secondary structures formed by β-peptide foldamers. Among the five known β-peptide helices, the 12-helix is particularly interesting because the internal hydrogen bond orientation and macrodipole are analogous to those of α-peptide helices (α-helix and 310-helix). The β-peptide 12-helix is defined by i, i+3 C - O•••H-N backbone hydrogen bonds and promoted by β-residues with a five-membered ring constraint. The 12-helical scaffold has been used to generate β-peptides with specific biological functions, for which diverse side chains must be properly placed along the backbone and, upon folding, properly arranged in space. Only two crystal structures of 12-helical β-peptides have previously been reported, both for homooligomers of trans-2-aminocyclopentanecarboxylic acid (ACPC). Here we report five additional crystal structures of 12-helical β-peptides, all containing residues that bear side chains. Four of the crystallized β-peptides include trans-4,4-dimethyl-2-aminocyclopentanecarboxylic acid (dm-ACPC) residues, and the fifth contains a β3-hPhe residue. These five β-peptides adopt fully folded 12-helical conformations in the solid state. The new crystal structures, along with previously reported data, allow a detailed characterization of the 12-helical conformation; average backbone torsion angles of β-residues and helical parameters are derived. These structural parameters are found to be similar to those for i, i+3 C = O⋯H-N hydrogen-bonded helices formed by other peptide backbones generated from α- and/or β-amino acids. The similarity between the conformational behavior of dm-ACPC and ACPC is consistent with previous NMR-based conclusions that 4,4-disubstituted ACPC derivatives are compatible with 12-helical folding. In addition, our data show how a β3-residue is accommodated in the 12-helix, thus enhancing understanding of the diverse conformational behavior of this flexible class of β-amino acids.
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U2 - 10.1021/ja1062532
DO - 10.1021/ja1062532
M3 - Article
C2 - 20828159
AN - SCOPUS:77957302949
VL - 132
SP - 13879
EP - 13885
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 39
ER -