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Nanoparticles containing magnetic materials, such as magnetite (Fe3O4), are particularly useful for imaging and separation techniques. As these nanoparticles are generally considered to be biologically and chemically inert, they are typically coated with metal catalysts, antibodies or enzymes to increase their functionality as separation agents. Here, we(More)
The yeast non-Mendelian factor [URE3] propagates by a prion-like mechanism, involving aggregation of the chromosomally encoded protein Ure2. The [URE3] phenotype is equivalent to loss of function of Ure2, a protein involved in regulation of nitrogen metabolism. The prion-like behaviour of Ure2 in vivo is dependent on the first 65 amino acid residues of its(More)
We have analysed the conformational states of barnase that are bound by the molecular chaperones GroEL and SecB. Line broadening in the NMR spectra of barnase in the presence of chaperone indicates binding of the native state of barnase to both GroEL and SecB, with a dissociation constant of > 3 x 10(-4) M for the GroEL-native barnase complex. GroEL and(More)
Ure2p is the precursor protein of the Saccharomyces cerevisiae prion [URE3]. Ure2p shows homology to glutathione transferases but lacks typical glutathione transferase activity. A recent study found that deletion of the Ure2 gene causes increased sensitivity to heavy metal ions and oxidants, whereas prion strains show normal sensitivity. To demonstrate that(More)
Hydrogen-deuterium exchange of 39 amide protons of Bacillus amyloliquefaciens ribonuclease (barnase) was analyzed by two-dimensional nuclear magnetic resonance in the presence of micromolar concentrations of the molecular chaperones GroEL and SecB. Both chaperones bound to native barnase under physiological conditions and catalyzed exchange of deeply buried(More)
Ure2 is the protein determinant of the [URE3] prion phenotype in Saccharomyces cerevisiae and consists of a flexible N-terminal prion-determining domain and a globular C-terminal glutathione transferase-like domain. Overexpression of the type I Hsp40 member Ydj1 in yeast cells has been found to result in the loss of [URE3]. However, the mechanism of prion(More)
GSTs (glutathione transferases) are an important class of enzymes involved in cellular detoxification. GSTs are found in all classes of organisms and are implicated in resistance towards drugs, pesticides, herbicides and antibiotics. The activity, structure and folding, particularly of eukaryotic GSTs, have therefore been widely studied. The crystal(More)
Views about the importance of the role of molluscicides in the integrated control of human schistosomiasis have passed through cyclical changes over the past 15 years. For a time, it was hoped that chemotherapy alone would achieve significant morbidity control; it has since become clear that molluscicides cannot be easily excluded from the anti-schistosome(More)
Trigger factor (TF) is the first chaperone encountered by the nascent chain in bacteria and forms a stoichiometric complex with the ribosome. However, the functional significance of the high cytosolic concentration of uncomplexed TF, the majority of which is dimeric, is unknown. To gain insight into TF function, we investigated the TF concentration(More)
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(More)