FEBS Letters 2013-03-18

Striking stabilization of Rana catesbeiana ribonuclease 3 by guanidine hydrochloride.

Magali Solé, Wolfgang Brandt, Ulrich Arnold

Index: FEBS Lett. 587(6) , 737-42, (2013)

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Abstract

Unfolding by chemical denaturants and the linear extrapolation method are widely used to determine the free energy of proteins. Ribonuclease 3 from bullfrog shows an extraordinary behavior in guanidinium hydrochloride in comparison to its homologues ribonuclease A and onconase with a high transition midpoint of denaturation but an apparently low cooperativity. The analysis of the interdependence of thermal, urea-, and guanidine hydrochloride-induced unfolding revealed that whereas addition of urea resulted in the expected destabilization of all three proteins, guanidine hydrochloride acted diversely: in contrast to ribonuclease A and onconase, both of which were destabilized as expected, low concentrations of guanidine hydrochloride significantly stabilize ribonuclease 3 from bullfrog. This stabilizing effect was endorsed by in silico docking studies.Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.