A5034544861- Glycosylation and Glycoproteins Research
- Bacteriophages and microbial interactions
- Bacterial Genetics and Biotechnology
- Carbohydrate Chemistry and Synthesis
- Escherichia coli research studies
- Viral gastroenteritis research and epidemiology
- Genomics and Phylogenetic Studies
- Enzyme Production and Characterization
- RNA Interference and Gene Delivery
- Immune Response and Inflammation
- Legume Nitrogen Fixing Symbiosis
- Salmonella and Campylobacter epidemiology
- Antibiotic Resistance in Bacteria
- Plant nutrient uptake and metabolism
- Pneumonia and Respiratory Infections
- Anaerobic Digestion and Biogas Production
- Protein purification and stability
- Mosquito-borne diseases and control
- Toxin Mechanisms and Immunotoxins
- Bacterial Infections and Vaccines
- RNA regulation and disease
- Cancer, Hypoxia, and Metabolism
- Probiotics and Fermented Foods
- RNA and protein synthesis mechanisms
- Galectins and Cancer Biology
Spital Limmattal
2016-2023
ETH Zurich
2006-2010
École Polytechnique Fédérale de Lausanne
2000-2006
Board of the Swiss Federal Institutes of Technology
1998-2006
Iowa State University
2006
Western University
2005
Imperial College London
2005
Campylobacter jejuni has a general N-linked protein glycosylation system that can be functionally transferred to Escherichia coli. In this study, we engineered E. coli cells in way two different pathways, N-glycosylation and lipopolysaccharide (LPS) biosynthesis, converge at the step which PglB, key enzyme of C. system, transfers O polysaccharide from lipid carrier (undecaprenyl pyrophosphate) an acceptor protein. PglB was only bacterial machinery both necessary sufficient for transfer. The...
Klebsiella pneumoniae is considered an urgent health concern due to the emergence of multi-drug-resistant strains for which vaccination offers a potential remedy. Vaccines based on surface polysaccharides are highly promising but need address high diversity surface-exposed polysaccharides, synthesized as O-antigens (lipopolysaccharide, LPS) and K-antigens (capsule polysaccharide, CPS), present in K. . We comprehensive clinically relevant study O- K-antigen biosynthesis gene clusters across...
N-linked protein glycosylation is found in all domains of life. In eukaryotes, it the most abundant modification secretory and membrane proteins, process coupled to translocation folding. We that bacteria, N-glycosylation can occur independently machinery. an vitro assay, bacterial oligosaccharyltransferase glycosylated a folded endogenous substrate with high efficiency bovine ribonuclease A low efficiency. Unfolding eukaryotic greatly increased glycosylation. propose system, sites are...
The PglB oligosaccharyltransferase (OTase) of Campylobacter jejuni can be functionally expressed in Escherichia coli, and its relaxed oligosaccharide substrate specificity allows the transfer different glycans from lipid carrier undecaprenyl pyrophosphate to an acceptor protein. To investigate PglB, we tested a set lipid-linked polysaccharides E. coli Salmonella enterica serovar Typhimurium. A hexose linked C-6 monosaccharide at reducing end did not inhibit O antigen However, required...
Conjugate vaccines in which polysaccharide antigens are covalently linked to carrier proteins belong the most effective and safest against bacterial pathogens. State-of-the art production of conjugate using chemical methods is a laborious, multi-step process. In vivo enzymatic coupling general glycosylation pathway Campylobacter jejuni recombinant Escherichia coli has been suggested as simpler method for producing vaccines. this study we describe biosynthesis two novel vaccine candidates...
Staphylococcus aureus is a leading cause of superficial and invasive human disease that often refractory to antimicrobial therapy. Vaccines have the potential reduce morbidity, mortality, economic impact associated with staphylococcal infections. However, single-component vaccines targeting S. failed show efficacy in clinical trials.A novel glycoengineering technology for creation multicomponent vaccine described. Genes encoding capsular polysaccharide (CP) biosynthesis, PglB (a...
Conjugate vaccines belong to the most efficient preventive measures against life-threatening bacterial infections. Functional expression of N -oligosaccharyltransferase ( -OST) PglB Campylobacter jejuni in Escherichia coli enables a simplified production glycoconjugate prokaryotic cells. Polysaccharide antigens pathogenic bacteria can be covalently coupled immunogenic acceptor proteins bearing engineered glycosylation sites. Transfer efficiency Cj is low for certain heterologous...
Although there is great interest in three-dimensional structures of glycoproteins and complex oligosaccharides, their structural determination have been hampered by inhomogeneous incomplete glycosylation, poor expression, low tendency to crystallize, severe chemical shift overlap. Using segmental labeling the glycan protein component vitro we developed a novel method NMR that overcomes some these problems. Highly homogeneously glycosylated proteins milligram amounts can be obtained. This...
Carbapenemase and extended β-lactamase-producing Klebsiella pneumoniae isolates represent a major health threat, stimulating increasing interest in immunotherapeutic approaches for combating infections. Lipopolysaccharide O antigen polysaccharides offer viable targets development, several studies have described protection with O-specific antibodies animal models of infection. O1 is produced by almost half clinical isolates. The polysaccharide backbone structure known, but monoclonal raised...
A number of proteobacteria carry the genetic information to perform N-linked glycosylation, but only protein glycosylation (pgl) pathway Campylobacter jejuni has been studied date. Here, we report that pgl gene cluster lari encodes for a functional machinery can be reconstituted in Escherichia coli. We determined N-glycan produced this system consisted linear hexasaccharide. found oligosaccharyltransferase (OST) C. conserved predominant specificity primary sequence D/E-X(-1)-N-X(+1)-S/T...
Shigellosis remains a major cause of diarrheal disease in developing countries and causes substantial morbidity mortality children. Glycoconjugate vaccines consisting bacterial surface polysaccharides conjugated to carrier proteins are the most effective for controlling invasive infections. Nevertheless, development multivalent conjugate vaccine prevent has been hampered by complex manufacturing process as polysaccharide each strain requires extraction, hydrolysis, chemical activation...
The lipid carrier specificity of the protein N-glycosylation enzyme C. jejuni PglB was tested using a logical, synthetic array natural and unnatural C10, C20, C30, C40 polyisoprenol sugar pyrophosphates, including those bearing repeating cis-prenyl units. Unusual, short, synthetically accessible C20 prenols (nerylnerol 1d geranylnerol 1e) were shown to be effective carriers for substrates. Kinetic analyses revealed clear K(M)-only modulation with chain length, thereby implicating successful...
Abstract Shigellosis remains a major cause of diarrheal disease in developing countries and causes substantial morbidity mortality children. Vaccination represents promising preventive measure to fight the burden disease, but despite enormous efforts, an efficacious vaccine is not available date. The use innovative biosynthetic Escherichia coli glycosylation system substantially simplifies production multivalent conjugate prevent shigellosis. This bioconjugation approach has been used...
The Vi capsular polysaccharide (CPS) of Salmonella enterica serovar Typhi, the cause human typhoid, is important for infectivity and virulence. biosynthetic machinery encoded within viaB locus composed 10 genes involved in regulation expression (tviA), polymer synthesis (tviB-tviE), cell surface localization CPS (vexA-vexE). We cloned from S. Typhi transposon insertion mutants individual were characterized Escherichia coli DH5α. Phenotype analysis revealed that tviB, tviC, tviD tviE are...
Abstract Background Protein glycosylation is of fundamental importance in many biological systems. The discovery N-glycosylation bacteria and the functional expression N-oligosaccharyltransferase PglB Campylobacter jejuni Escherichia coli enabled production engineered glycoproteins study underlying molecular mechanisms. A particularly promising application for protein recombinant potent conjugate vaccines where polysaccharide antigens pathogenic are covalently bound to immunogenic carrier...
Extraintestinal pathogenic Escherichia coli (ExPEC) cause a wide range of clinical diseases such as bacteremia and urinary tract infections. The increase multidrug resistant ExPEC strains is becoming major concern for the treatment these infections E. has been identified critical priority pathogen by WHO. Therefore, development vaccines become increasingly important, with surface lipopolysaccharide constituting promising vaccine target. This study presents genetic structural analysis urine...
ABSTRACT Expression of the dnaKJ and groESL 1 heat shock operons Bradyrhizobium japonicum depends on a ς 32 -like transcription factor. Three such factors (RpoH , RpoH 2 3 ) have previously been identified in this organism. We report here that they direct from some but not all -type promoters when respective rpoH genes are expressed Escherichia coli . All three were purified as soluble C-terminally histidine-tagged proteins, although bulk overproduced was insoluble. The proteins recognized...