Pressure denaturation of the yeast prion protein Ure2.
Denaturation of the Saccharomyces cerevisiae prion protein Ure2 was investigated using hydrostatic pressure. Pressures of up to 600 MPa caused only limited perturbation of the structure of the 40-kDa dimeric protein. However, nondenaturing concentrations of GdmCl in combination with high pressure resulted in complete unfolding of Ure2 as judged by intrinsic fluorescence. The free energy of unfolding measured by pressure denaturation or by GdmCl denaturation is the same, indicating that pressure does not induce dimer dissociation or population of intermediates in 2 M GdmCl. Pressure-induced changes in 5 M GdmCl suggest residual structure in the denatured state. Cold denaturation under pressure at 200 MPa showed that unfolding begins below -5 degrees C and Ure2 is more susceptible to cold denaturation at low ionic strength. Results obtained using two related protein constructs, which lack all or part of the N-terminal prion domain, were very similar.
Zhou
J M
JM
National Laboratory of Biomacromolecules, Chinese Academy of Sciences, Beijing, China 100101.
Zhu
L
L
Balny
C
C
Perrett
S
S
D003080:Cold Temperature; D005656:Fungal Proteins / Q000737:chemistry* / Q000187:drug effects; D005979:Glutathione Peroxidase; D019791:Guanidine / Q000494:pharmacology; D011312:Pressure; D011328:Prions / Q000737:chemistry*; D011487:Protein Conformation / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D011328:Prions; D029701:Saccharomyces cerevisiae Proteins; D005979:Glutathione Peroxidase; C067020:URE2 protein, S cerevisiae; D019791:Guanidine