Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
Skip to main content

Thermodynamic aspects of protein stabilization by two widespread naturally occurring osmolytes, beta-hydroxyectoine and betaine, were studied using differential scanning calorimetry (DSC) and bovine ribonuclease A (RNase A) as a model protein. The osmolyte beta-hydroxyectoine purified from Marinococcus was found to be a very efficient stabilizer. At a concentration of 3M it increased the melting temperature of RNase A (Tm) by more than 12K and gave rise to a stability increase of 10.6kJ/mol at room temperature. The heat capacity difference between the folded and unfolded state (deltaC(p)) was found to be significantly increased. Betaine stabilized RNase A only at concentrations less than 3M. Also, here deltaCp was found to be increased. Calculation of the number of water molecules that additionally bind to unfolded RNase A resulted in surprisingly low numbers for both osmolytes. The significant stabilization of RNase A by beta-hydroxyectoine makes this osmolyte an interesting stabilizer in biotechnological processes in which enzymes are applied in the presence of denaturants or at high temperature.

Type

Journal article

Journal

Extremophiles

Publication Date

08/1999

Volume

3

Pages

191 - 198

Keywords

Amino Acids, Diamino, Animals, Betaine, Calorimetry, Differential Scanning, Cattle, Gram-Positive Bacteria, Protein Denaturation, Ribonuclease, Pancreatic, Thermodynamics