Search results for "Peptide Mapping"
showing 10 items of 32 documents
Impact of sewage sludges on Medicago truncatula symbiotic proteome
2004
The effects of sewage sludges were investigated on the symbiotic interactions between the model plant Medicago truncatula and the arbuscular mycorrhizal fungus Glomus mosseae or the rhizobial bacteria Sinorhizobium meliloti. By comparison to a control sludge showing positive effects on plant growth and root symbioses, sludges enriched with polycylic aromatic hydrocarbons or heavy metals were deleterious. Symbiosis-related proteins were detected and identified by two-dimensional electrophoresis and matrix-assisted laser desorption ionization mass spectrometry, and image analysis was used to study the effects of sewage sludges on M. truncatula symbiotic proteome.
Shell palaeoproteomics: first application of peptide mass fingerprinting for the rapid identification of mollusc shells in archaeology.
2020
10 pages; International audience; Molluscs were one of the most widely-used natural resources in the past, and their shells are abundant among archaeological findings. However, our knowledge of the variety of shells that were circulating in prehistoric times (and thus their socio-economic and cultural value) is scarce due to the difficulty of achieving taxonomic determination of fragmented and/or worked remains. This study aims to obtain molecular barcodes based on peptide mass fingerprints (PMFs) of intracrystalline proteins, in order to obtain shell identification. Palaeoproteomic applications on shells are challenging, due to low concentration of molluscan proteins and an incomplete unde…
The Fumarate/Succinate Antiporter DcuB of Escherichia coli Is a Bifunctional Protein with Sites for Regulation of DcuS-dependent Gene Expression
2008
DcuB of Escherichia coli catalyzes C4-dicarboxylate/succinate antiport during growth by fumarate respiration. The expression of genes of fumarate respiration, including the genes for DcuB (dcuB) and fumarate reductase (frdABCD) is transcriptionally activated by C4-dicarboxylates via the DcuS-DcuR two-component system, comprising the sensor kinase DcuS, which contains a periplasmic sensing domain for C4-dicarboxylates. Deletion or inactivation of dcuB caused constitutive expression of DcuS-regulated genes in the absence of C4-dicarboxylates. The effect was specific for DcuB and not observed after inactivation of the homologous DcuA or the more distantly related DcuC transporter. Random and s…
Type I keratin cDNAs from the rainbow trout: independent radiation of keratins in fish
2002
Five different type I keratins from a teleost fish, the rainbow trout Oncorhynchus mykiss, have been sequenced by cDNA cloning and identified at the protein level by peptide mass mapping using MALDI-MS. This showed that the entire range of type I keratins detected biochemically in this fish has now been sequenced. Three of the keratins are expressed in the epidermis (subtype Ie), whereas the other two occur in simple epithelia and mesenchymal cells (subtype Is). Among the Is keratins is an ortholog of human K18; the second Is polypeptide is clearly distinct from K18. We raised a new monoclonal antibody (F1F2, subclass IgG1) that specifically recognizes trout Is keratins, with negative react…
An automated on-line multidimensional HPLC system for protein and peptide mapping with integrated sample preparation.
2002
A comprehensive on-line two-dimensional 2D-HPLC system with integrated sample preparation was developed for the analysis of proteins and peptides with a molecular weight below 20 kDa. The system setup provided fast separations and high resolving power and is considered to be a complementary technique to 2D gel electrophoresis in proteomics. The on-line system reproducibly resolved approximately 1000 peaks within the total analysis time of 96 min and avoided sample losses by off-line sample handling. The low-molecular-weight target analytes were separated from the matrix using novel silica-based restricted access materials (RAM) with ion exchange functionalities. The size-selective sample fr…
Protein mapping by two-dimensional high performance liquid chromatography.
2000
Current developments in drug discovery in the pharmaceutical industry require highly efficient analytical systems for protein mapping providing high resolution, robustness, sensitivity, reproducibility and a high throughput of samples. The potential of two-dimensional (2D) HPLC as a complementary method to 2D-gel electrophoresis is investigated, especially in view of speed and repeatability. The method will be applied for proteins of a molecular mass <20 000 which are not well resolved in 2D-gel electrophoresis. The 2D-HPLC system described in this work consisted of anion- or cation-exchange chromatography in the first dimension and reversed-phase chromatography in the second dimension. We …
Identification of protein IT of the intestinal cytoskeleton as a novel type I cytokeratin with unusual properties and expression patterns.
1990
A major cytoskeletal polypeptide (Mr approximately 46,000; protein IT) of human intestinal epithelium was characterized by biochemical and immunological methods. The polypeptide, which was identified as a specific and genuine mRNA product by translation in vitro, reacted, in immunoblotting after SDS-PAGE, only with one of numerous cytokeratin (CK) antisera tested but with none of many monoclonal CK antibodies. In vitro, it formed heterotypic complexes with the type II CK 8, as shown by blot binding assays and gel electrophoresis in 4 M urea, and these complexes assembled into intermediate filaments (IFs) under appropriate conditions. A chymotrypsin-resistant Mr approximately 38,000 core fra…
Mapping the protein composition oftrans-Golgi network (TGN)-derived carrier vesicles from polarized MDCK cells
1998
In polarized MDCK cells, proteins and lipids are sorted in the trans-Golgi network /TGN) and packaged into different vesicular carriers that are delivered to the apical or basolateral cell surface. To gain insight into the sorting and trafficking machinery, we have previously isolated TGN-derived carrier vesicles from perforated MDCK cells. The composition of immuno-isolated apical and basolateral carriers was mapped by two-dimensional (2-D) gel electrophoresis. Here we describe the identification of several components of the vesicle fraction by using three different methods. 2-D gel comigration was performed with carrier vesicles isolated from metabolically labeled MDCK cells and human epi…
Different conformations of nascent polypeptides during translocation across the ER membrane
2000
Abstract Background In eukaryotic cells, proteins are translocated across the ER membrane through a continuous ribosome-translocon channel. It is unclear to what extent proteins can fold already within the ribosome-translocon channel, and previous studies suggest that only a limited degree of folding (such as the formation of isolated α-helices) may be possible within the ribosome. Results We have previously shown that the conformation of nascent polypeptide chains in transit through the ribosome-translocon complex can be probed by measuring the number of residues required to span the distance between the ribosomal P-site and the lumenally disposed active site of the oligosaccharyl transfer…
Evolution of tissue-specific keratins as deduced from novel cDNA sequences of the lungfish Protopterus aethiopicus.
2005
Lungfishes are possibly the closest extant relatives of the land vertebrates (tetrapods). We report here the cDNA and predicted amino acid sequences of 13 different keratins (ten type I and three type II) of the lungfish Protopterus aethiopicus. These keratins include the orthologs of human K8 and K18. The lungfish keratins were also identified in tissue extracts using two-dimensional polyacrylamide gel electrophoresis, keratin blot binding assays and immunoblotting. The identified keratin spots were analyzed by peptide mass fingerprinting which assigned seven sequences (inclusively Protopterus K8 and K18) to their respective protein spot. The peptide mass fingerprints also revealed the fac…