Effect of dimethyl sulphoxide on the crystal structure of porcine pepsin

Kesavulu, Muppuru Muni and Ramasubramanian, Sundaramoorthy and Suguna, Kaza (2005) Effect of dimethyl sulphoxide on the crystal structure of porcine pepsin. In: Biochemical and Biophysical Research Communications, 331 (4). pp. 1510-1514.

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Abstract

The structure of porcine pepsin crystallized in the presence of dimethyl sulphoxide has been analysed by X-ray crystallography to obtain insights into the structural events that occur at the onset of chemical denaturation of proteins. The results show that one dimethyl sulphoxide molecule occupies a site on the surface of pepsin interacting with two of its residues. An increase in the average temperature factor of pepsin in the presence of dimethyl sulphoxide has been observed indicating protein destabilization induced by the denaturant. Significant increase in the temperature factor and weakening of the electron density have been observed for the catalytic water molecule located between the active as partates. The conformation of pepsin remains unchanged in the crystal structure. However, the enzyme assay and circular dichroism studies indicate that dimethylsulphoxide causes a slight change in the secondary structure and complete loss of activity of pepsin in solution.

Item Type:	Journal Article
Publication:	Biochemical and Biophysical Research Communications
Publisher:	Academic Press Inc Elsevier Science
Additional Information:	Copyright for this article belongs to Elsevier.
Keywords:	Pepsin;Dimethyl sulphoxide;Protein denaturation
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	06 Jul 2005
Last Modified:	19 Sep 2010 04:19
URI:	http://eprints.iisc.ac.in/id/eprint/3318

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