ABSTRACT: The aim of the study was to separate the proteins from Naja ashei venom with the use of SEC followed by IEX in order to obtain and functionally characterize purified toxins.
Project description:The study aimed to fractionate Naja ashei venom with Size-exclusion chromatography to obtain fractions with significantly lower complexity than crude venom. MS analysis allowed to estimate the percentage of different protein groups in each fraction, thus providing information about the extent of homogeneity in each collected sample. High purity fractions can be used to study the effects of particular proteins on different biological targets. Samples with greater complexity can be further purified using different analytical methods.
Project description:In contrast to comprehensively investigated antibacterial activity of snake venoms, namely crude venoms and their selected components, little is known about antifungal properties of elapid snake venoms. In the present study, the proteome of two venoms of red spitting cobra Naja pallida (NPV) and Mozambique spitting cobra Naja mossambica (NMV) was characterized using LC-MS/MS approach and the biological activity of crude venoms against three Candida species was established.
Project description:Protein expression is regulated by production and degradation of mRNAs and proteins, but their specific relationships remain unknown. We combine measurements of protein production and degradation and mRNA dynamics to build a quantitative genomic model of the differential regulation of gene expression in LPS stimulated mouse dendritic cells. Changes in mRNA abundance play a dominant role in determining most dynamic fold changes in protein levels. Conversely, the preexisting proteome of proteins performing basic cellular functions is remodeled primarily through changes in protein production or degradation, accounting for over half of the absolute change in protein molecules in the cell. Thus, the proteome is regulated by transcriptional induction of novel cellular functions and remodeling of preexisting functions through the protein life cycle. Mouse primary dendritic cells were treated with LPS or mock stimulus and profiled over a 12-hour time course. Cells were grown in M-labeled SILAC media, which was replaced with H-labeled SILAC media at time 0. Aliquots were taken at 0, 0.5, 1, 2, 3, 4, 5, 6, 9, and 12 hours post-stimulation and added to equal volumes of a master mix of unlabeled (L) cells for the purpose of normalization. RNA-Seq was performed at 0, 1, 2, 4, 6, 9, and 12 hours post-stimulation.
Project description:We used a combination of morphological, behavioural, proteomic and transcriptomic data to show that venom and telopodal gland systems of Lithobius forficatus are serial homologues that were convergently weaponized to function in predation and defence.
Project description:The venom of cone snails is highly variable both between and within species, as well as spatially along the venom duct. However, defferences of defensive and predatory venoms in "hook-and-line" fish hunting clades and their venom duct origins has not been investigated. In this study a combination of proteomics and transcriptomic approaches were used to decode the venom profiles of C. striatus from the Pionoconus clade. The raw data files obtained from the reduced alkylated and digested venom duct sections (distal, central and proximal), injected predatory and defensive induced venoms are submitted here.
Project description:Previously, we constructed a coculture model to analyze the effect of macrophages on intestinal epithelial cells, and found that TNF-a secreted from human macrophage-like THP-1 cells induced cell damage to intestinal epithelial Caco-2 cells (Exp.Cell.Res. 2006, 312(19):3909-19). In this study, we present activation of NF-kB in Caco-2 cells within 15 min after coculturing. To reveal how TNF-a secreted from THP-1 cells affects Caco-2 cells in an early stage of coculture, we exhaustively analyzed the changes of gene expression in Caco-2 cells cocultured with THP-1 cells over the time periods of 0, 1, 3, 6, 24, and 48 h by using a DNA microarray. Differentially expressed genes extracted with maSigPro demonstrated that IEX-1 was the lowest p-value gene, that is, the most significantly changed gene among the up-regulated genes. The genes expressed in a similar pattern to IEX-1 involved immunity, apoptosis, and protein kinase cascade. These findings suggest that the stimuli of TNF-a from THP-1 cells activates NF-kB, leading induction of various gene expression. This pattern of gene expression indicates that not only early defense response but also cell death occurs at the same time, causing inflammatory condition.
Project description:The emergence and spread of carbapenem-resistant Klebsiella pneumoniae (CR-KPN) infections have worsened the current situation worldwide. Clinically, cotrimoxazole (CTX) and amikacin (AMI) are considered to be the preferred drugs in the treatment of (CR-KPN). But for now, the extensive use of cotrimoxazole (CTX) and amikacin (AMI) During the course of treatment leads to the emergence of cotrimoxazole- and amikacin-resistant infections, which is of great clinical concern. Previous evidence has shown that bacteria with reduced metabolism tend to be resistant to antibiotics, however, the mechanism remains unclear. In the present study, proteomics was performed on the sensitive, cotrimoxazole-resistant, amikacin-resistant and cotrimoxazole/amikacin-both-resistant KPN clinical isolates, and 2266 proteins were identified in total by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) analysis. Further bioinformatic analysis showed down-regulation of tricarboxylic acid cycle pathway and up-regulation of alcohol metabolic or glutathione metabolism processes, which may contribute to ROS clearance and cell survival, in drug-resistant isolates. Finally, combined with minimum inhibitory concentration (MIC) of Amikacin and Cotrimoxazole on different KPN isolates, we identified nine proteins contributed mostly to such an alteration and the survival of bacteria under drug pressure, which could reveal novel mechanisms or pathways involved in drug resistance. These proteins and their pathways might be used as targets for the development of novel therapeutics against antimicrobial-resistant (AMR) infections.
Project description:A comparative proteomic study of two Raphidiopsis raciborskii strains with different toxigenicities in response to varied iron concentrations under nitrogen fixing conditions
Project description:M. aeruginosa PCC7806 was cultured in iron-limiting Fraquil media under chemostat conditions. Four dilution rates were chosen to study the organism’s response to iron limitation at different stages of the growth curve.