Stabilization of Enzyme Structures by Inhibitors: A Nuclear Magnetic Resonance Study of the Effect of Phosphate on the Acid Unfolding of Ribonuclease A

Das, Manoj K and Vithayathil, Paul J and Balaram, P (1977) Stabilization of Enzyme Structures by Inhibitors: A Nuclear Magnetic Resonance Study of the Effect of Phosphate on the Acid Unfolding of Ribonuclease A. In: International Journal of Peptide and Protein Research, 10 . pp. 9-16.

PDF 10(1977).pdf Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The acid denaturation of bovine pancreatic ribonuclease A in the presence of 0.2 M sodium dihydrogen phosphate has been studied by n.m.r spectroscopy. Phenylalanine, tyrosine and methionine resonances serve as monitors of the unfolding process. It is shown that the inhibitor shifts the equilibrium towards the native structure at acid pH. Exchange broadening of the C-2 resonances of the active site histidines, 12 and 119, occurs in the presence of phosphate, suggesting an equilibrium between native and unfolded structures. Stabilization of the partially unfolded protein is observed at pH 1.5, as evidenced by the lack of the histidine resonance due to random coil protein. A scheme of the equilibria relating the various states of protein is proposed.

Item Type:	Journal Article
Publication:	International Journal of Peptide and Protein Research
Publisher:	Munksgaard International Publishers
Additional Information:	No part may be reproduced by any process without written permission from the author(s)
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit Division of Biological Sciences > Biochemistry
Date Deposited:	05 Apr 2005
Last Modified:	19 Sep 2010 04:14
URI:	http://eprints.iisc.ac.in/id/eprint/1161

Actions (login required)

View Item