The thermal stability of bovine pancreatic ribonuclease (RNase A) has been investigated in the presence of trimethylamine N-oxide (TMAO), a naturally occurring osmolyte, by means of differential scanning calorimetry (DSC) and circular dichroism (CD) measurements at neutral and acid pH conditions. It is well known that compatible osmolytes such as TMAO are effective in stabilizing protein structure and counteracting the denaturing effect of urea and GuHCl. Calorimetric results show that TMAO stabilizes RNAse A at pH 7.0 and does not stabilize the protein at pH 4.0. RNase A thermal denaturation in the presence of TMAO is a reversible two-state N ⇄ D process. We also show that TMAO counteracts the urea and guanidinium hydrochloride (GuHCl) denaturing effect at neutral pH, whereas the counteracting ability is lost at acid pH.
The effect of trimethylamine N-oxide on RNase A stability:a DSC study / F., Foglia; Carullo, Paola; DEL VECCHIO, POMPEA GIUSEPPINA GRAZIA. - In: JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY. - ISSN 1388-6150. - STAMPA. - 91:1(2008), pp. 67-72. [1388-6150]
The effect of trimethylamine N-oxide on RNase A stability:a DSC study
CARULLO, PAOLA;DEL VECCHIO, POMPEA GIUSEPPINA GRAZIA
2008
Abstract
The thermal stability of bovine pancreatic ribonuclease (RNase A) has been investigated in the presence of trimethylamine N-oxide (TMAO), a naturally occurring osmolyte, by means of differential scanning calorimetry (DSC) and circular dichroism (CD) measurements at neutral and acid pH conditions. It is well known that compatible osmolytes such as TMAO are effective in stabilizing protein structure and counteracting the denaturing effect of urea and GuHCl. Calorimetric results show that TMAO stabilizes RNAse A at pH 7.0 and does not stabilize the protein at pH 4.0. RNase A thermal denaturation in the presence of TMAO is a reversible two-state N ⇄ D process. We also show that TMAO counteracts the urea and guanidinium hydrochloride (GuHCl) denaturing effect at neutral pH, whereas the counteracting ability is lost at acid pH.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
