@article {508, title = {Soni-removal of nucleic acids from inclusion bodies. [Protein Technology Core]}, journal = {Biochem Biophys Res Commun}, volume = {448}, year = {2014}, month = {2014 May 23}, pages = {45-9}, abstract = {

Inclusion bodies (IBs) are commonly formed in Escherichia coli due to over expression of recombinant proteins in non-native state. Isolation, denaturation and refolding of these IBs is generally performed to obtain functional protein. However, during this process IBs tend to form non-specific interactions with sheared nucleic acids from the genome, thus getting carried over into downstream processes. This may hinder the refolding of IBs into their native state. To circumvent this, we demonstrate a methodology termed soni-removal which involves disruption of nucleic acid-inclusion body interaction using sonication; followed by solvent based separation. As opposed to conventional techniques that use enzymes and column-based separations, soni-removal is a cost effective alternative for complete elimination of buried and/or strongly bound short nucleic acid contaminants from IBs.

}, keywords = {Antigens, CD44, Cell Fractionation, Dengue Virus, Inclusion Bodies, Nucleic Acids, Protein Denaturation, Protein Folding, Recombinant Proteins, Solubility, Sonication, Viral Envelope Proteins}, issn = {1090-2104}, doi = {10.1016/j.bbrc.2014.04.049}, author = {Neerathilingam, Muniasamy and Mysore, Sumukh and Gandham, Sai Hari A} } @article {718, title = {Development of the structural core and of conformational heterogeneity during the conversion of oligomers of the mouse prion protein to worm-like amyloid fibrils.}, journal = {J Mol Biol}, volume = {423}, year = {2012}, month = {2012 Oct 19}, pages = {217-31}, abstract = {

Understanding how structure develops during the course of amyloid fibril formation by the prion protein is important for understanding prion diseases. Determining how conformational heterogeneity manifests itself in the fibrillar and pre-fibrillar amyloid aggregates is critical for understanding prion strain phenotypes. In this study, the formation of worm-like amyloid fibrils by the mouse prion protein has been characterized structurally by hydrogen-deuterium exchange coupled to mass spectrometry. The structural cores of these fibrils and of the oligomer on the direct pathway of amyloid fibril formation have been defined, showing how structure develops during fibril formation. The structural core of the oligomer not on the direct pathway has also been defined, allowing the delineation of the structural features that make this off-pathway oligomer incompetent to directly form fibrils. Sequence segments that exhibit multiple local conformations in the three amyloid aggregates have been identified, and the development of structural heterogeneity during fibril formation has been characterized. It is shown that conformational heterogeneity is not restricted to only the C-terminal domain region, which forms the structural core of the aggregates; it manifests itself in the N-terminal domain of the protein as well. Importantly, all three amyloid aggregates are shown to be capable of disrupting lipid membrane structure, pointing to a mechanism by which they may be toxic.

}, keywords = {Amino Acid Sequence, Amyloid, Animals, Deuterium Exchange Measurement, Kinetics, Mice, Models, Molecular, Molecular Sequence Data, Prion Proteins, Prions, Protein Conformation, Protein Folding}, issn = {1089-8638}, doi = {10.1016/j.jmb.2012.06.040}, author = {Singh, Jogender and Sabareesan, A T and Mathew, M K and Udgaonkar, Jayant B} }