X-ray studies on crystalline complexes involving amino acids and peptides. XXXIX. crystal structures of malonic acid complexes of DL- and L-histidine. preservation of aggregation pattern on reversal of chirality

Saraswathi, NT and Vijayan, M (2002) X-ray studies on crystalline complexes involving amino acids and peptides. XXXIX. crystal structures of malonic acid complexes of DL- and L-histidine. preservation of aggregation pattern on reversal of chirality. In: Acta Crystallographica Section B, 58 (4). pp. 734-739.

PDF X-ray_studies.pdf - Published Version Restricted to Registered users only Download (695kB) | Request a copy

Abstract

The malonic acid complexes of DL- and L-histidine are made up of zwitterionic positively charged histidinium ions and semimalonate (hydrogen malonate) ions. They crystallise in space groups P2(1)/n and P2(1), respectively, with nearly the same unit-cell parameters. The molecules aggregate in the two complexes in a remarkably similar manner. The two sets of crystallographically independent molecules are related by a pseudo-glide plane. This pseudo-symmetry is almost exact except in the case of the alpha-carboxylate group and, to some extent, the alpha-C and the alpha-N atoms. Preservation of the aggregation pattern to such an extent on the reversal of chirality of half the amino-acid molecules is observed for the first time in amino-acid complexes. This is achieved at the cost of considerable conformational strain in one of the two histidinium ions in the L-histidine complex.

Item Type:	Journal Article
Publication:	Acta Crystallographica Section B
Publisher:	International Union of Crystallography
Additional Information:	Copyright belongs to International Union of Crystallography.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	27 Sep 2004
Last Modified:	16 Jan 2012 05:32
URI:	http://eprints.iisc.ac.in/id/eprint/2006

Actions (login required)

View Item