# $^{13}C-n.m.r.$ studies of the conformational changes in proline oligomers brought about by lithium and calcium salts

Rao, Ch Pulla and Balaram, P and Rao, CNR (1983) $^{13}C-n.m.r.$ studies of the conformational changes in proline oligomers brought about by lithium and calcium salts. In: International Journal of Biological Macromolecules, 5 (5). pp. 289-295.

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## Abstract

A detailed $^{13}C-n.m.r.$ investigation has been carried out on the conformational changes in proline oligomers brought about by interaction with lithium and calcium perchlorates. Interaction of lithium and calcium salts with Piv-$(Pro)_n$-OMe, n = 2, 4 and 5 results in trans-cis isomerization. In the case of pentaproline, metal salts also give rise to other trans-isomers caused by the rotation about the $C^\alpha-C(=O)$ bond (\Psi, cis'). Calcium salts seem to stabilize cis'-isomers and produce effects somewhat different from those of lithium salts.

Item Type: Journal Article Copyright of this article belongs to Elsevier Science B.V. Peptides;proline oligomers;13C-n.m.r.;peptide conformation;salt effects. Division of Chemical Sciences > Solid State & Structural Chemistry Unit 14 Jul 2008 19 Sep 2010 04:47 http://eprints.iisc.ernet.in/id/eprint/15005