Anti or gauche? trans-β2,3-Amino acid residues that are known to promote extended structures in their peptides show specific rotamer preferences in response to an intramolecular hydrogen-bonding possibility, which facilitates the 11-helical structures in their 1:1 α,β-hybrid peptides (see figure). Preferences for the gauche conformation for all internal β residues and anti for the C-terminal residue in these peptides were confirmed by NMR spectroscopic and X-ray diffraction experiments. Copyright © 2012 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

Kannoth Manheri Muraleedharan

Department Of Chemistry

Amino acid residues

Extended structures

FOLDAMERS

GAUCHE CONFORMATION

Helical structures

HYBRID PEPTIDES

ROTAMERS

Hydrogen

Nuclear magnetic resonance spectroscopy

Peptides

X ray diffraction

Amino acids

amino acid

peptide

article

chemical structure

chemistry

nuclear magnetic resonance

protein conformation

protein secondary structure

Stereoisomerism

synthesis

X ray crystallography

Crystallography, X-Ray

Molecular Structure

Nuclear Magnetic Resonance, Biomolecular

Protein Structure, Secondary

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IIT Madras

Chemistry - A European Journal

Fine-tuning the gelation ability of aryl triazolyl peptide 1 by C-terminal modification led to the identification of 2 with the remarkable ability to form highly transparent gels in a wide range of solvents including oils. Good rheological properties, effective phase-selective gelation in short time periods, and usefulness in dye removal from water are the other highlights. © The Royal Society of Chemistry 2016.

RSC Advances

Aryl-triazolyl peptides for efficient phase selective gelation and easy removal of dyes from water

Unfolding of helical trans-β2,3-hybrid peptides with (α-β)nα composition, when executed by increasing solvent polarity or temperature, proceeded in a systematic manner with the turns unwinding sequentially; C-terminal region of these peptides were first to unwind and the process propagated towards N terminus with more and more β residues equilibrating from the gauche to the anti rotameric state across Cα£Cβ. This is evidenced by clear change in their CβH signal splitting, 3JCαH-CβH values, and sequential disappearance of i,i+2 NOEs. Helix-strand hybrid: Unfolding of helical trans-β2,3-hybrid peptides with (α-β)nα composition when executed by increasing solvent polarity or temperature, proceeded in a systematic manner with the turns unwinding sequentially; the C-terminal region of these peptides were first to unwind and the process propagated towards the N terminus with more and more β residues equilibrating from gauche to anti rotameric states across Cα£Cβ. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Can Helical Peptides Unwind One Turn at a Time? - Controlled Conformational Transitions in α,β2,3-Hybrid Peptides

The ability of α,β2,3-hybrid peptides with a heterochiral backbone to exist in a helical, extended, or partially folded state depending on the solvation conditions employed was investigated. The preference was found to be directly dictated by Cα-Cβ torsions in the β-residues. α,β-Hybrid peptides with a heterochiral backbone show the ability to exist in a helical, extended, or partially folded conformation depending on the solvation conditions employed. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

European Journal of Organic Chemistry

Conformational Switching in Heterochiral α,β2,3-Hybrid Peptides in Response to Solvent Polarity

Chemical environment-dependent supramolecular assembly of 11-helical α,β2,3-hybrid peptide which give hexagonal or rod-like microcrystalline structures is demonstrated. Apart from the modulatory role by P123, sequential use of organic co-solvents during the initiation and propagation phases is shown to contribute to the size and shape regulation during molecular organization. Comparison of powder XRD data and thermal analysis results suggested that the molecular arrangement in these aggregates is similar to that in their crystals. © 2012 The Royal Society of Chemistry.

Soft Matter

Chemical environment as control element in the evolution of shapes-'hexagons and rods' from an 11-helical α,β2,3- hybrid peptide

Variations in the lattice arrangement and the tendency toward isomorphic behavior in a group of trans-β2,3 amino acid derivatives with Boc and oxazolidinone moieties at the N- and C-terminals are discussed. The substitution pattern at the α- and β positions in these systems was found to give different torsional preferences and hence different molecular organizations in their crystals. Analysis of such preferences in their azide analogs has unraveled the involvement of a relatively uncommon carbonyl-azide dipolar interaction in lattice stabilization. © 2010 American Chemical Society.

Crystal Growth and Design

Trans -β2,3-amino acid-based supramolecular synthons for probing the interrelationships between structure, torsion-directed assembly, and isomorphism

An efficient synthetic approach towards trans-β2,3-amino acids involving anti-selective aldol, azidation and controlled hydrolysis as key steps is discussed. Apart from structural elaboration of these building blocks to homo- and hetero-dipeptides, possibility of selective endocyclic cleavage of the chiral auxiliary was advantageously used in the preparation of α,β-hybrid peptide alcohols and corresponding aldehydes, which are promising candidates for biological evaluation against proteases of therapeutic interest. © 2009 Elsevier Ltd. All rights reserved.

Tetrahedron

An efficient synthetic approach towards trans-β2,3-amino acids and demonstration of their utility in the design of therapeutically important β2,3-peptides and α,β2,3-peptide aldehydes

Reference Module in Chemistry, Molecular Sciences and Chemical Engineering

Cambridge Crystallographic Data Centre (CCDC)

The Leading Edge

Editorial Calendar

American Heart Journal

Unprecedented torsional preferences in trans-β2,3-amino acid residues and formation of 11-helices in α,β2,3-hybrid peptides

Journal	Chemistry - A European Journal
ISSN	09476539
Open Access	No