It is presented a study concerning the influence of guanidinium chloride (GuHCl) and urea on thermal stability of Bovine Pancreatic Ribonuclease A (RNAase A) at differentpH values. As expected, at increasing the denaturant concentration, the protein thermostability decreases. This is shown by a decrease of both the thermodynamic parameters, temperature and heat effect, characterising the denaturation process. In order to analyse the calorimetric curves we adopt a statistical thermodynamic approach. The individual one-dimensional DSC profiles have been expanded into another dimension by varying the GuHCl concentration, so that a heat capacity surface is defined for eachpH. By means of the ICARUS program, developed in our laboratory, we accomplish a two dimensional deconvolution of the experimental data linking the binding equilibrium to the denaturation process. This analysis provides a well founded and complete statistical thermodynamic characterisation of denaturation process of RNAase A in the presence of GuHCl and allows to calculate the thermodynamic parameters associated to the binding of denaturant molecule.
|Titolo:||Thermodynamic Characterization of RNAase A in the Presence of Urea and GuHCl|
|Parole Chiave:||denaturation models; guanidinium chloride; micro-DSC; ribonuclease A; urea|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
Settore BIO/10 - Biochimica
|Data di pubblicazione:||1994|
|Digital Object Identifier (DOI):||10.1007/BF02549930|
|Appare nelle tipologie:||01 - Articolo su periodico|