Effect of stabilizing additives on the structure and hydration of proteins: a study involving monoclinic lysozyme

Saraswathi, NT and Sankaranarayanan, R and Vijayan, M (2002) Effect of stabilizing additives on the structure and hydration of proteins: a study involving monoclinic lysozyme. In: Acta Crystallographica Section D: Biological Crystallography, 58 (7). pp. 1162-1167.

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Abstract

In pursuance of a long-range programme on the hydration, mobility and action of proteins, the structural basis of the stabilizing effect of sugars and polyols is being investigated. With two crystallographically independent molecules with slightly different packing environments in the crystal, monoclinic lysozyme constitutes an ideal system for exploring the problem. The differences in the structure and hydration of the two molecules provide a framework for examining the changes caused by stabilizing additives. Monoclinic crystals were grown under native conditions and also in the presence of 10% sucrose, 15% trehalose, 10% trehalose, 10% sorbitol and 5% glycerol. The crystal structures were reÆned at resolutions ranging from 1.8 to 2.1 A . The average B values, and hence the mobility of the structure, are lower in the presence of additives than in the native crystals. However, a comparison of the structures indicates that the effect of the additives on the structure and the hydration shell around the protein molecule is considerably less than that caused by differences in packing. It is also less than that caused by the replacement of NaNO3 by NaCl as the precipitant in the crystallization experiments. This result is not in conformity with the commonly held belief that additives exert their stabilizing effect through the reorganization of the hydration shell, at least as far as the ordered water molecules are concerned.

Item Type:	Journal Article
Publication:	Acta Crystallographica Section D: Biological Crystallography
Publisher:	International Union of Crystallography
Additional Information:	The copyright for this article belongs to International Union of Crystallography.
Keywords:	proteins hydration;monoclinic lysozyme;stabilizing additives
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	15 Oct 2004
Last Modified:	19 Sep 2010 04:16
URI:	http://eprints.iisc.ac.in/id/eprint/2098

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