Peptides foldamers

Constrained y9 -amino acids in which the C(2)-C(3) bond is part of a small ring (5- and 6-membered rings) have been used extensively by GeUman (tra s-2-amino-cycloalkanecarboxyhc acids 33—42) and others (43 and 44) for the preparation of stable y9-peptide foldamers (Fig. 2.7). 

De Jong, R., Rijkers, D. T. S., and Liskamp, R. M. J. (2002) Automated solid-phase synthesis and structural investigation of /3-peptidosulfonamides and /3-peptidosulfonamide//J-peptide hybrids /J-peptidosulfonamide and /3-peptide foldamers are two of a different kind. Helv. Chim. Acta 85,4230 1243. 

Price JL, Horne WS, Gellman SH. Discrete heterogeneous quaternary structure formed by a/p-peptide foldamers and a-peptides. J. Am. Chem. Soc. 2007 129 6376-6377. 

Crisma M, Moretto A, Toniolo C, Kaczmarek K, Zabrocki J. First rigid peptide foldamers with an alternating cis-trans amide sequence. An oligomeric building block for the construction of new helices, large-ring cyclic correlates, and nanombes. Macromolecules 2001 34 5048-5052. 

Stephens OM et al (2005) Inhibiting HIV fusion with a beta-peptide foldamer. J Am Chem Soc 127(38) 13126-13127... 

Fig. 22 a-Helix and a/(3-peptide foldamers array side-chain functionality in similar fashion (a) backbone sequences of a-, (3-, and a/(3-helices, and structures of cyclic [3-residues, (b) Comparison of the a- and a/fS-helices (PDB codes 2ZTA and 3C3F) (Reprinted from Guarracino and Arora [139], Copyright (2009) with permission from Elsevier)... 

Home WS, Johnson LM, Ketas TJ et al (2009) Structural and biological mimicry of protein surface recognition by a/P-peptide foldamers. Proc Natl Acad Sci USA 106 14751-14756... 

Molecular Electronics Bio-Sensors and Bio-Computers R 86 M. Venanzi, A. Palleschi, L. Stella and B. Pispisa, Peptide Foldamers as Building Blocks for Ordered Nanomolecular Architectures A Structural Investigation , p. 237 Vol. 98,2003... 

Figure 11.11 Click reactions of azido-substituted helical peptide foldamers.

Oba, M., Takazaki, H., Kawabe, N., Doi, M., Demizu, Y., Kurihara, M., Kawakubo, M., Nagano, M., Suemune, H., Tanaka, M. (2014). Helical Peptide-Foldamers Having a Chiral Five-Membered Ring Amino Acid with Two Azido Functional Groups. The Journal of Organic Chemistry, 79, 9125—9140. 

The secondary structures of aliphatic peptidic foldamers are highly diverse and strongly dependent on substitution patterns and on constrained rings within each residue. The success, breadth, and rapidity of their development have been remarkable. Given the first reports of tertiary and quaternary structures based on /S-peptides (Section 4.3), one may safely predict considerable developments in this field in the near future. 

The Relevance of Low-Barrier Hydrogen Bonds to Enzymatic Catalysis 179 P-Peptide Foldamers 180... 

This reaction has been applied to the synthesis of oxetane p-amino acids mainly by the Fleet s group and oxetane 5-amino acids by Ranter s group, in collaboration with Wessel s group, in order to smdy the potential of oxetane amino acids as monomers for p-/5-peptide foldamers, a class of unnatural oligomers with propensities to adopt specific and compact conformations for potential clinical applications. 

Synthetic peptide dendrimers, catalytic antibodies, RNA catalysts, peptide foldamers as well as other native or modified enzymes with completely different fxmctions were discovered to catalyze carbon-carbon bond formation [15]. 4-Oxalocrotonate tau-tomerase (4-OT) catalyzes in vivo the conversion of 2-hydroxy-2,4-hexadienedioate (136) to 2-oxo-3-hexenedioate (137) (Scheme 10.33a), and it belongs to the catabolic pathway for aromatic hydrocarbons in P. putida mt-2 [200]. This enzyme carries a catalytic amino-terminal proline, which could act as catalyst in the same fashion as the proline mediated by organocatalytic reactions. Initial studies demonstrate that this enzyme was able to catalyze aldol condensations of acetaldehyde to a variety of electrophiles 138 (Scheme 10.33b) [200]. This enzyme was also examined as a potential catalyst for carbon-carbon bond forming Michael-type reactions of acetaldehyde to nitroolefins 139 (Scheme 10.33c) [201,202]. 

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