2024-03-29T09:26:54Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/2458562022-12-30T20:07:10Zcom_10261_34com_10261_5col_10261_287
2021-07-14T12:10:12Z
urn:hdl:10261/245856
Destabilizing mutations alter the hydrogen exchange mechanism in Ribonuclease A
Bruix, M.
Ribó, M.
Benito, A.
Laurents, D.V.
Rico, Manuel
Vilanova, María
Ministerio de Educación y Ciencia (España)
9 pags, 6 figs
The effect of strongly destabilizing mutations, I106A and V108G of Ribonuclease A (RNase A), on its structure and stability has been determined by NMR. The solution structures of these variants are essentially equivalent to RNase A. The exchange rates of the most protected amide protons in RNase A (35°C), the I106A variant (35°C), and the V108G variant (10°C) yield stability values of 9.9, 6.0, and 6.8 kcal/mol, respectively, when analyzed assuming an EX2 exchange mechanism. Thus, the destabilization induced b y these mutations is propagated throughout the protein. Simulation of RNase A hydrogen exchange indicates that the most protected protons in RNase A and the V108G variant exchange via the EX2 regime, whereas those of I106A exchange through a mixed EX1 + EX2 process. It is striking that a single point mutation can alter the overall exchange mechanism. Thus, destabilizing mutations joins high temperatures, high pH and the presence of denaturating agents as a factor that induces EX1 exchange in proteins. The calculations also indicate a shift from the EX2 to the EX1 mechanism for less protected groups within the same protein. This should be borne in mind when interpreting exchange data as a measure of local stability in less protected regions. © 2008 by the Biophysical Society.
2021-07-14T12:10:12Z
2021-07-14T12:10:12Z
2008-03-15
2021-07-14T12:10:13Z
artículo
Biophysical Journal 94: 2297-2305 (2008)
http://hdl.handle.net/10261/245856
10.1529/biophysj.107.122952
18192347
Publisher's version
http://dx.doi.org/10.1529/biophysj.107.122952
Sí
MEC/BFU2005-01855/BMC
MEC/BFU2006-15543-CO2-02
openAccess
Biophysical Society