Dataset Information

Mass spectroscopic analysis of Sup35NM prion polymerization.

ABSTRACT: Sup35NM, the prion determining domain of the protein responsible for the yeast prion phenomenon [Psi], has become a powerful model for studying key processes in amyloid-related human diseases. One of these processes is a conformational conversion of soluble precursor protein into insoluble fibrillar structures. In this study, we created a set of Sup35NM mutants and used proteolytic digestion coupled with mass spectroscopy to monitor local structure of the protein during polymerization. Experimental data were compared to a network model and showed that during the conformational conversion residue Arg-28 became highly protected from cleavage, residue Arg-98 remained partially solvent exposed, and residues between 28 and 98 showed an intermediate degree of protection. In addition, we found that a distinct subset of proteolytic polypeptides spanning 28-98 residues segment spontaneously formed stable dimers. This finding suggests that the [29-98] region is the key interacting region of Sup35NM responsible for amyloid conversion.

SUBMITTER: Goncharov VA

PROVIDER: S-EPMC1366979 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mass spectroscopic analysis of Sup35NM prion polymerization.

Goncharov Vladimir A VA

Biophysical journal 20050930 6

Sup35NM, the prion determining domain of the protein responsible for the yeast prion phenomenon [Psi], has become a powerful model for studying key processes in amyloid-related human diseases. One of these processes is a conformational conversion of soluble precursor protein into insoluble fibrillar structures. In this study, we created a set of Sup35NM mutants and used proteolytic digestion coupled with mass spectroscopy to monitor local structure of the protein during polymerization. Experimen ...[more]

PMID: 16199512

Similar Datasets

Project description:The brain functions through chemical interactions between many different cell types, including neurons and glia. Acquiring comprehensive information on complex, heterogeneous systems requires multiple analytical tools, each of which have unique chemical specificity and spatial resolution. Multimodal imaging generates complementary chemical information via spatially localized molecular maps, ideally from the same sample, but requires method enhancements that span from data acquisition to interpretation. We devised a protocol for performing matrix-assisted laser desorption/ionization (MALDI)-Fourier transform ion cyclotron resonance-mass spectrometry imaging (MSI), followed by infrared (IR) spectroscopic imaging on the same specimen. Multimodal measurements from the same tissue provide precise spatial alignment between modalities, enabling more advanced image processing such as image fusion and sharpening. Performing MSI first produces higher quality data from each technique compared to performing IR imaging before MSI. The difference is likely due to fixing the tissue section during MALDI matrix removal, thereby preventing analyte degradation occurring during IR imaging from an unfixed specimen. Leveraging the unique capabilities of each modality, we utilized pan sharpening of MS (mass spectrometry) ion images with selected bands from IR spectroscopy and midlevel data fusion. In comparison to sharpening with histological images, pan sharpening can employ a plethora of IR bands, producing sharpened MS images while retaining the fidelity of the initial ion images. Using Laplacian pyramid sharpening, we determine the localization of several lipids present within the hippocampus with high mass accuracy at 5 μm pixel widths. Further, through midlevel data fusion of the imaging data sets combined with k-means clustering, the combined data set discriminates between additional anatomical structures unrecognized by the individual imaging approaches. Significant differences between molecular ion abundances are detected between relevant structures within the hippocampus, such as the CA1 and CA3 regions. Our methodology provides high quality multiplex and multimodal chemical imaging of the same tissue sample, enabling more advanced data processing and analysis routines.

Dataset Information

Mass spectroscopic analysis of Sup35NM prion polymerization.

Publications

Mass spectroscopic analysis of Sup35NM prion polymerization.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets