ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Aggregation modes in sheets formed by protected $ {\beta}$ -aminoacids and ${\beta}$-peptides

Sengupta, Anindita and Rituparna S, Roy and Sabareesh, Varatharajan and Narayanaswamy, Shamala and Padmanabhan, Balaram (2006) Aggregation modes in sheets formed by protected $ {\beta}$ -aminoacids and ${\beta}$-peptides. In: Organic & Biomolecular Chemistry, 4 (6). pp. 1166-1173.

[img] PDF
8.pdf - Published Version
Restricted to Registered users only

Download (386kB) | Request a copy
Official URL: http://www.rsc.org/ej/OB/2006/b516088j.pdf


The crystal structures of four protected ${\beta}$-amino acid residues,Boc-(S)-${\beta}{^3}$-HAla-NHMe(1);Boc-(R)-${\beta}{^3}$-HVal-NHMe(2);Boc-(S)-${\beta}{^3}$-HPhe-NHMe(3);Boc-(S)-${\beta}{^3}$-HPro-OH(6) and two ${\beta}$-dipeptides,Boc-(R)-${\beta}{^3}$-HVal-(R)-${\beta}{^3}$-HVal-OMe(4);Boc-(R)-${\beta}{^3}$-HVal-(S)-${\beta}{^3}$ HVal-OMe(5) have been determined. Gauche conformations about the $C{^\beta}$ –$C{^\alpha}$ bonds$(\theta{\sim}{\pm}60){^o}$ are observed for the ${\beta}{^3}$-HPhe residues in 3 and all four ${\beta}{^3}$-HVal residues in the dipeptides 4 and 5. Trans conformations $(\theta{\sim}180{^0})$ are observed for ${\beta}{^3}$-HAla residues in both independent molecules in 1 and for the ${\beta}{^3}$-HVal and ${\beta}{^3}$-HPro residues in 2 and 6, respectively. In the cases of compounds 1–5, molecules associate in the crystals via intermolecular backbone hydrogen bonds leading to the formation of sheets. The polar strands formed by ${\beta}{^3}$-residues aggregate in both parallel(1, 3, 5) and antiparallel (2, 4) fashion. Sheet formation accommodates both the trans and gauche conformations about the $C{^\beta}$-$C{^\alpha}$ bonds.

Item Type: Journal Article
Additional Information: Copyright of this article belongs to Royal Society of Chemistry.
Keywords: Chemistry,Organic; Alpha-Amino;Secondary Structure;Hybrid Peptides;Hairpin;Foldamers;Sequences;Residues;Spectroscopy;Hexapeptide;Segments
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Depositing User: NG Nishad
Date Deposited: 03 Dec 2008 07:01
Last Modified: 19 Sep 2010 04:53
URI: http://eprints.iisc.ac.in/id/eprint/16723

Actions (login required)

View Item View Item