Publications by authors named "Wieslaw Swietnicki"

Carbon metabolism plays an important role in bacterial physiology and pathogenesis. The type III secretion system (T3SS) of is a virulence factor that contributes to acute infections. It has been demonstrated that bacterial metabolism affects the T3SS.

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Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections.

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is an opportunistic human pathogen that has become a nosocomial health problem worldwide. The pathogen has multiple drug removal and virulence secretion systems, is resistant to many antibiotics, and there is no commercial vaccine against it. is a zoonotic pathogen that is on the Select Agents list.

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is an oral human pathogen. The bacterium destroys dental tissue and is a serious health problem worldwide. Experimental data and bioinformatic analysis revealed that the pathogen produces three types of lipopolysaccharides (LPS): normal (O-type), anionic (A-type), and capsular (K-type).

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is one of the most prominent opportunistic bacteria in airways of cystic fibrosis patients and in immunocompromised patients. These bacteria share the same polymicrobial niche with other microbes, such as the opportunistic fungus Their inter-kingdom interactions and diverse exchange of secreted metabolites are responsible for how they both fare in competition for ecological niches. The outcomes of their contests likely determine persistent damage and degeneration of lung function.

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Bacteriophage base tailplate proteins were recently discovered to have hydrolytic activity towards disaccharides. The putative assignment of sugar binding sites was based on known lectin structures and identified residues a.a.

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Pseudomonas aeruginosa is an opportunistic pathogen infecting human population. The pathogen is becoming a serious health problem due to its ability to evade normal immune response of the host and multiple drug resistance to many antibiotics. The pathogen has 2 major virulence systems of which the type III secretion system (T3SS) is of major concern to humans.

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Staphylococcus aureus is a human pathogen rapidly becoming a serious health problem due to ease of acquiring antibiotic resistance. To help identify potential new drug candidates effective against the pathogen, a small focused library was screened for inhibition of bacterial growth against several pathogens, including S. aureus.

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Enteropathogenic E. coli (EPEC) is a human pathogen using type III secretion system for delivery of proteins directly into the human host. The system contains a single ATPase, EscN, which is essential for uncoupling of proteins from their complexes with chaperones before the delivery.

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In the present study, we evaluated the antitumor effect of two synthetic analogs of vitamin D, namely PRI-2191 [(24R)-1,24-dihydroxyvitamin D3] and PRI-2205 (5,6-trans calcipotriol), in combined human colon HT-29 cancer treatment with 5-fluorouracil (5-FU). Mice bearing HT-29 tumors transplanted subcutaneously or orthotopically were injected with vitamin D analogs and 5-FU in various schedules. A statistically significant inhibition of subcutaneous or orthotopic tumor growth was observed as a result of combined therapy.

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Prion diseases, or transmissible spongiform encephalopathies (TSEs), are associated with the conformational conversion of the cellular prion protein, PrP(C), into a protease-resistant form, PrP(Sc). Here, we show that mutation-induced thermodynamic stabilization of the folded, α-helical domain of PrP(C) has a dramatic inhibitory effect on the conformational conversion of prion protein in vitro, as well as on the propagation of TSE disease in vivo. Transgenic mice expressing a human prion protein variant with increased thermodynamic stability were found to be much more resistant to infection with the TSE agent than those expressing wild-type human prion protein, in both the primary passage and three subsequent subpassages.

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Autosomal dominant mutations in BTB and Kelch domain containing 13 protein (KBTBD13) are associated with a new type of Nemaline Myopathy (NEM). NEM is a genetically heterogeneous group of muscle disorders. Mutations causing phenotypically distinct NEM variants have previously been identified in components of muscle thin filament.

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Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr.

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Yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. The pathogen uses a type III secretion system (T3SS) to deliver virulence factors directly from bacterium into host mammalian cells. The system contains a single ATPase, YscN, necessary for delivery of virulence factors.

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Yersinia pestis, a human and animal pathogen, uses the type III secretion system (T3SS) for delivering virulence factors and effectors into the host cells. The system is conserved in animal pathogens and is hypothesized to deliver the virulence factors directly from bacterial to mammalian cells through a pore composed of YopB and YopD translocation proteins. The YopB and YopD translocator proteins must be delivered first to form a functional pore in the mammalian cell.

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The successful expression and purification of proteins in an active form is essential for structural and biochemical studies. With rapid advances in genome sequencing and high-throughput structural biology, an increasing number of proteins are being identified as potential drug targets but are difficult to obtain in a form suitable for structural or biochemical studies. Although prokaryotic recombinant expression systems are often used, proteins obtained in this way are typically found to be insoluble.

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Yersinia pestis is a gram-negative human pathogen that uses a type III secretion system to deliver virulence factors into human hosts. The delivery is contact-dependent and it has been proposed that polymerization of Yop secretion protein F (YscF) is used to puncture mammalian cell membranes to facilitate delivery of Yersinia outer protein effectors into host cells. To evaluate the potential immunogenicity and protective efficacy of YscF against Y.

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Binary complexes formed by components of the Yersinia pestis type III secretion system were investigated by surface plasmon resonance (SPR) and matrix-assisted laser desorption time-of-flight mass spectrometry. Pairwise interactions between 15 recombinant Yersinia outer proteins (Yops), regulators, and chaperones were first identified by SPR. Mass spectrometry confirmed over 80% of the protein-protein interactions suggested by SPR, and new binding partners were further characterized.

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Streptococcal pyrogenic enterotoxin C (Spe-C) is a superantigen virulence factor produced by Streptococcus pyogenes that activates T-cells polyclonally. The biologically active form of Spe-C is thought to be a homodimer containing an essential zinc coordination site on each subunit, consisting of the residues His(167), His(201), and Asp(203). Crystallographic data suggested that receptor specificity is dependent on contacts between the zinc coordination site of Spe-C and the beta-chain of the major histocompatibility complex type II (MHCII) molecule.

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The function of the cellular prion protein (PrPC) remains obscure. Studies suggest that PrPC functions in several processes including signal transduction and Cu2+ metabolism. PrPC has also been established to bind nucleic acids.

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