Difference spectroscopic studies on binding of Cibacron blue F3GA to ribosome inactivating proteins: effect of beta-mercaptoethanol on the interaction with ricin

Sharma, Shalini and Podder, Sunil K (1998) Difference spectroscopic studies on binding of Cibacron blue F3GA to ribosome inactivating proteins: effect of beta-mercaptoethanol on the interaction with ricin. In: Journal of Biosciences, 23 (03). pp. 225-233.

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Abstract

The interaction of Cibacron blue F3GA with ribosome inactivating proteins, ricin, ricin A-chain and momordin has been investigated using difference absorption spectroscopy. Ricin was found to bind the dye with a 20- and 2-fold lower affinity than ricin A-chain and momordin, respectively. A time dependent increase in the amplitude of Cibacron blue difference spectrum in the presence of ricin was observed on addition of beta-mercaptoethanol. Analysis of the kinetic profile of this increase showed a biphasic phenomenon and the observed rates were found to be independent of the concentration of beta-mercaptoethanol. Kinetics of reduction of the intersubunit disulphide bond in ricin by beta-mercaptoethanol showed that reduction pet se is a second order reaction. Therefore, the observed changes in the difference spectra of Cibacron blue probably indicate a slow change in the conformation of ricin, triggered by reduction of the intersubunit disulphide bond.

Item Type:	Journal Article
Publication:	Journal of Biosciences
Publisher:	Indian Academy Of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy Of Sciences.
Keywords:	ribosome inactivating proteins;ricin;ricin A-chain; momordin;Cibacron blue;difference spectra.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	11 May 2009 08:45
Last Modified:	19 Sep 2010 05:28
URI:	http://eprints.iisc.ac.in/id/eprint/19505

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