Cleavage sites are identified by SDS-PAGE and N-terminal sequencing. We observe well-defined cleavage fragments, which suggest that flexibility is limited to certain regions of the protein. Cleavage sites for alpha-lactalbumin and myoglobin correspond to regions identified in other studies as partially unfolded at low pH or in the presence of organic solvents. For Tnfn3, which does
not form partially folded structures under other conditions, cleavage sites can be rationalized from the structure of the proteins folding transition state and the position of loops in the native state. Nevertheless, they are more sensitive to choice of surfactant and protease, probably reflecting a heterogeneous and fluctuating ensemble of partially unfolded structures. Thus, for proteins accumulating stable intermediates on the folding pathway, surfactants encourage the formation of these states, while the situation is more complex FK228 supplier for proteins that do not form these intermediates. (C) 2008 Wiley Periodicals, Inc. Biopolymers 91: 221-231, 2009.”
“P>In yeast cells infected GSK3326595 solubility dmso with the [PSI+] prion, Sup35p forms aggregates and its activity in translation termination is downregulated. Transfection experiments have shown that Sup35p filaments assembled in vitro are infectious, suggesting that they reproduce or closely resemble the prion. We have used
several EM techniques to study the molecular architecture of filaments, seeking clues as to the mechanism of downregulation. Sup35p has an N-terminal ‘prion’ domain; a highly charged middle (M-)domain; and
a C-terminal domain with the translation termination activity. By negative staining, cryo-EM and scanning transmission EM (STEM), filaments of full-length Sup35p show a thin backbone fibril surrounded by a diffuse 65-nm-wide cloud of globular C-domains. In diameter (similar to 8 nm) and appearance, the backbones resemble amyloid fibrils Crenigacestat price of N-domains alone. STEM mass-per-unit-length data yield similar to 1 subunit per 0.47 nm for N-fibrils, NM-filaments and Sup35p filaments, further supporting the fibril backbone model. The 30 nm radial span of decorating C-domains indicates that the M-domains assume highly extended conformations, offering an explanation for the residual Sup35p activity in infected cells, whereby the C-domains remain free enough to interact with ribosomes.”
“Introduction: Cryoprecipitate and its byproduct, cryosupernatant plasma (CSP) have been used to treat specific medical diseases such as hemophilia, von Willebrand disease and thrombotic thrombocytopenia purpura. Cryoprecipitate is also widely used to prepare fibrin glue. In many instances, it is given to augment fresh frozen plasma when patients are bleeding. However, the full range of constituents of cryoprecipitate and CSP are not widely appreciated.