@misc{KunstmannEngstroemWehleetal.2020,
  author    = {Kunstmann, Ruth Sonja and Engstr{\"o}m, Olof and Wehle, Marko and Widmalm, G{\"o}ran and Santer, Mark and Barbirz, Stefanie},
  title     = {Increasing the affinity of an O-Antigen polysaccharide binding site in Shigella flexneri bacteriophage Sf6 tailspike protein},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {32},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51941},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-519418},
  pages     = {13},
  year      = {2020},
  abstract  = {Broad and unspecific use of antibiotics accelerates spread of resistances. Sensitive and robust pathogen detection is thus important for a more targeted application. Bacteriophages contain a large repertoire of pathogen-binding proteins. These tailspike proteins (TSP) often bind surface glycans and represent a promising design platform for specific pathogen sensors. We analysed bacteriophage Sf6 TSP that recognizes the O-polysaccharide of dysentery-causing Shigella flexneri to develop variants with increased sensitivity for sensor applications. Ligand polyrhamnose backbone conformations were obtained from 2D H-1,H-1-trNOESY NMR utilizing methine-methine and methine-methyl correlations. They agreed well with conformations obtained from molecular dynamics (MD), validating the method for further predictions. In a set of mutants, MD predicted ligand flexibilities that were in good correlation with binding strength as confirmed on immobilized S. flexneri O-polysaccharide (PS) with surface plasmon resonance. In silico approaches combined with rapid screening on PS surfaces hence provide valuable strategies for TSP-based pathogen sensor design.},
  language  = {en}
}
@misc{GeorgievGrafmuellerBlegeretal.2018,
  author    = {Georgiev, Vasil N. and Grafm{\"u}ller, Andrea and Bl{\´e}ger, David and Hecht, Stefan and Kunstmann, Ruth Sonja and Barbirz, Stefanie and Lipowsky, Reinhard and Dimova, Rumiana},
  title     = {Area increase and budding in giant vesicles triggered by light},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  volume    = {5},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {733},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42629},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426298},
  pages     = {9},
  year      = {2018},
  abstract  = {Biomembranes are constantly remodeled and in cells, these processes are controlled and modulated by an assortment of membrane proteins. Here, it is shown that such remodeling can also be induced by photoresponsive molecules. The morphological control of giant vesicles in the presence of a water-soluble ortho-tetrafluoroazobenzene photoswitch (F-azo) is demonstrated and it is shown that the shape transformations are based on an increase in membrane area and generation of spontaneous curvature. The vesicles exhibit budding and the buds can be retracted by using light of a different wavelength. In the presence of F-azo, the membrane area can increase by more than 5\% as assessed from vesicle electrodeformation. To elucidate the underlying molecular mechanism and the partitioning of F-azo in the membrane, molecular dynamics simulations are employed. Comparison with theoretically calculated shapes reveals that the budded shapes are governed by curvature elasticity, that the spontaneous curvature can be decomposed into a local and a nonlocal contribution, and that the local spontaneous curvature is about 1/(2.5 mu m). The results show that exo- and endocytotic events can be controlled by light and that these photoinduced processes provide an attractive method to change membrane area and morphology.},
  language  = {en}
}
@misc{KunstmannScheidtBuchwaldetal.2018,
  author    = {Kunstmann, Ruth Sonja and Scheidt, Tom and Buchwald, Saskia and Helm, Alexandra and Mulard, Laurence A. and Fruth, Angelika and Barbirz, Stefanie},
  title     = {Bacteriophage Sf6 Tailspike Protein for Detection of Shigella flexneri Pathogens},
  series = {Viruses},
  journal   = {Viruses},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417831},
  pages     = {18},
  year      = {2018},
  abstract  = {Bacteriophage research is gaining more importance due to increasing antibiotic resistance. However, for treatment with bacteriophages, diagnostics have to be improved. Bacteriophages carry adhesion proteins, which bind to the bacterial cell surface, for example tailspike proteins (TSP) for specific recognition of bacterial O-antigen polysaccharide. TSP are highly stable proteins and thus might be suitable components for the integration into diagnostic tools. We used the TSP of bacteriophage Sf6 to establish two applications for detecting Shigella flexneri (S. flexneri), a highly contagious pathogen causing dysentery. We found that Sf6TSP not only bound O-antigen of S. flexneri serotype Y, but also the glucosylated O-antigen of serotype 2a. Moreover, mass spectrometry glycan analyses showed that Sf6TSP tolerated various O-acetyl modifications on these O-antigens. We established a microtiter plate-based ELISA like tailspike adsorption assay (ELITA) using a Strep-tag®II modified Sf6TSP. As sensitive screening alternative we produced a fluorescently labeled Sf6TSP via coupling to an environment sensitive dye. Binding of this probe to the S. flexneri O-antigen Y elicited a fluorescence intensity increase of 80\% with an emission maximum in the visible light range. The Sf6TSP probes thus offer a promising route to a highly specific and sensitive bacteriophage TSP-based Shigella detection system.},
  language  = {en}
}
@misc{SchmidtRabschBroekeretal.2017,
  author    = {Schmidt, Andreas and Rabsch, Wolfgang and Broeker, Nina K. and Barbirz, Stefanie},
  title     = {Bacteriophage tailspike protein based assay to monitor phase variable glucosylations in Salmonella O-antigens},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103769},
  pages     = {11},
  year      = {2017},
  abstract  = {Background Non-typhoid Salmonella Typhimurium (S. Typhimurium) accounts for a high number of registered salmonellosis cases, and O-serotyping is one important tool for monitoring epidemiology and spread of the disease. Moreover, variations in glucosylated O-antigens are related to immunogenicity and spread in the host. However, classical autoagglutination tests combined with the analysis of specific genetic markers cannot always reliably register phase variable glucose modifications expressed on Salmonella O-antigens and additional tools to monitor O-antigen glucosylation phenotypes of S. Typhimurium would be desirable. Results We developed a test for the phase variable O-antigen glucosylation state of S. Typhimurium using the tailspike proteins (TSP) of Salmonella phages 9NA and P22. We used this ELISA like tailspike adsorption (ELITA) assay to analyze a library of 44 Salmonella strains. ELITA was successful in discriminating strains that carried glucose 1-6 linked to the galactose of O-polysaccharide backbone (serotype O1) from non-glucosylated strains. This was shown by O-antigen compositional analyses of the respective strains with mass spectrometry and capillary electrophoresis. The ELITA test worked rapidly in a microtiter plate format and was highly O-antigen specific. Moreover, TSP as probes could also detect glucosylated strains in flow cytometry and distinguish multiphasic cultures differing in their glucosylation state. Conclusions Tailspike proteins contain large binding sites with precisely defined specificities and are therefore promising tools to be included in serotyping procedures as rapid serotyping agents in addition to antibodies. In this study, 9NA and P22TSP as probes could specifically distinguish glucosylation phenotypes of Salmonella on microtiter plate assays and in flow cytometry. This opens the possibility for flow sorting of cell populations for subsequent genetic analyses or for monitoring phase variations during large scale O-antigen preparations necessary for vaccine production.},
  language  = {en}
}
@phdthesis{Barbirz2005,
  author    = {Barbirz, Stefanie},
  title     = {Konservierte Struktur bei genetischer Mosaizit{\"a}t : die Tailspike Proteine dreier Phagen der Familie Podviridae},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6885},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {Die Tailspike Proteine (TSP) der Bakteriophagen P22, Sf6 und HK620 dienen der Erkennung von Kohlenhydratstrukturen auf ihren gram-negativen Wirtsbakterien und zeigen, von den ersten 110 Aminos{\"a}uren des N-Terminus abgesehen, keine Sequenz{\"u}bereinstimmung. Mit R{\"o}ntgenkristallstrukturanalyse konnte gezeigt werden, dass HK620TSP und Sf6TSP ebenfalls zu einer parallelen, rechtsg{\"a}ngigen beta-Helix falten, wie dies schon f{\"u}r P22TSP bekannt war. Die Kohlenhydratbindestelle ist bei Sf6TSP im Vergleich zu P22TSP zwischen die Untereinheiten verschoben.},
  subject      = {Bakteriophagen},
  language  = {de}
}