@phdthesis{Wortmann2008, author = {Wortmann, Sebastian}, title = {Das Tuberoinfundibul{\"a}re Peptid von 39 Aminos{\"a}uren (TIP39): Gen-Struktur und Expressionsmuster im Zebrafisch und M{\"a}usehirn}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32230}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Das Tuberoinfundibul{\"a}re Peptid von 39 Aminos{\"a}uren (TIP39), ein kurzes Oligopeptid mit einer N-terminalen und einer C-terminalen alpha-Helix, wurde urspr{\"u}nglich bei der Suche nach einem Liganden f{\"u}r den neu beschriebenen PTH2-Rezeptor aus einem Hypothalamus-Hypophysen-Extrakt isoliert. Aus der bisherigen Charakterisierung von TIP39 ist am meisten bekannt bez{\"u}glich der Expressions-Muster und der Interaktion am PTH2-Rezeptor. TIP39 ist der st{\"a}rkste bekannte Aktivator des PTH2-Rezeptors und wirkt am PTH1-Rezeptor als funktioneller Antagonist. Inzwischen wurde auch das TIP39 Gen des Menschen und der Maus charakterisiert. Die physiologische Rolle von TIP39 ist dennoch bisher weitgehend ungekl{\"a}rt, diskutiert werden Einfl{\"u}sse auf den Kalzium-Phosphat-Haushalt, die Hypothalamus-Hypophysen-Achse oder die Nozizeption. Der Schwerpunkt dieser Arbeit lag auf der Untersuchung des TIP39 kodierenden Gens des Zebrafischs danio rerio. Die komplette cDNA konnte amplifiziert werden und wurde unter der Accession No. AF486190 in der GenBank ver{\"o}ffentlicht. Der Genlocus konnte mittels Radiation Hybrid Mapping auf Chromosom 17 lokalisiert werden. Die 3 charakterisierten Exons und 2 Introns umfassen zusammen ca. 3750 bp. Daneben wurde die Prozessierung des Genprodukts aufgekl{\"a}rt: TIP39 wird beim Zebrafisch als Preprohormon translatiert, am N-terminalen Ende findet sich eine 25 Aminos{\"a}uren lange Signalsequenz, die f{\"u}r sezernierte Peptide typisch ist und welche f{\"u}r die Aufnahme in das Endoplasmatische Retikulum verantwortlich ist. In diesem Bereich finden sich eine weitgehende {\"U}bereinstimmungen zwischen den analysierten Spezies. Gefolgt wird die Zielsequenz von einem 93 Aminos{\"a}uren langen Zwischenpeptid, das sich als wenig konserviert zwischen den Spezies zeigt. Die eigentliche Sequenz von TIP39 beim Zebrafisch zeigte eine Sequenzhomologie von 59\% zur humanen Sequenz und wurde mittels Blast Suche als hochkonserviert in allen 12 untersuchten Spezies wiedergefunden. Im genomischen Southern-Blot zeigte sich, dass TIP39 beim Zebrafisch im einfachen Chromosomensatz ein „single-copy" Gen ist. Mittels RT-PCR konnte eine sehr fr{\"u}he erste Expression von TIP39 bereits ab 16 Stunden nach Fertilisation gezeigt werden. Im Bereich des supraoptischen Trakts des Zebrafischhirn konnte eine scharf umschriebene Zellpopulation mit starker TIP39-Expression detektiert werden. Durch Knockdown-Experimente konnte beim Zebrafisch gezeigt werden, dass ein Fehlen von TIP39 Expression w{\"a}hrend der Embryogenese zu einer Fehlentwicklung des Frontalhirns f{\"u}hrt und zudem mit einer Funktionsbeeintr{\"a}chtigung der Schwanzmotorik einhergeht. Hierf{\"u}r wurden gerade befruchteten Zebrafischeiern im Zwei-Zell-Stadium sogenannte „Morpholinos" injiiziert, welche als Antisense-Nukleotide spezifisch die Translation von TIP39 hemmen. Erg{\"a}nzend konnte im M{\"a}usehirn die Expression von TIP39 mittels in-situ Hybridisierung bestimmt werden. Es zeigte sich eine Expression von TIP39 in einer Vielzahl von klar umschriebenen Neuronengruppen, so im Hypothalamus, dem limbischen System und in sensorischen Neuronen, ohne dass sich im Einzelfall jeweils sicher eine Funktion hieraus ableiten l{\"a}sst. In der vorliegenden Arbeit konnte somit erstmals gezeigt werden, dass TIP39 zur korrekten Neurogenese bei der Entwicklung des Frontalhirns des Zebrafisches unabdingbar ist und auch die fr{\"u}he Entwicklung der Motoneurone durch TIP39 beeinflusst wird. Die ermittelten Daten unterst{\"u}tzen die Vorstellung von TIP39 als ein sezerniertes Neuropeptid, das als Transmitter in der Sensorik, insbesondere der Nozizeption, wirkt. Auch eine Beeinflussung der zentralnerv{\"o}sen Steuerung der Motorik durch TIP39 wird angenommen. Die gute Lokalisations-{\"U}bereinstimmung der Expressionen von TIP39 mit seinem zugeordneten Rezeptor, dem PTH2-Rezeptor, l{\"a}sst eine systemische endokrine Wirkung von TIP39 wenig wahrscheinlich erscheinen, sondern st{\"a}rkt die Hypothese von TIP39 als einem para-, bzw. autokrin wirkenden Neurotransmitter.}, subject = {Zebrab{\"a}rbling}, language = {de} } @article{vanDintherZhangWeidaueretal.2013, author = {van Dinther, Maarten and Zhang, Juan and Weidauer, Stella E. and Boschert, Verena and Muth, Eva-Maria and Knappik, Achim and de Gorter, David J. J. and van Kasteren, Puck B. and Frisch, Christian and M{\"u}ller, Thomas D. and ten Dijke, Peter}, title = {Anti-Sclerostin Antibody Inhibits Internalization of Sclerostin and Sclerostin-Mediated Antagonism of Wnt/LRP6 Signaling}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0062295}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130981}, pages = {e62295}, year = {2013}, abstract = {Sclerosteosis is a rare high bone mass disease that is caused by inactivating mutations in the SOST gene. Its gene product, Sclerostin, is a key negative regulator of bone formation and might therefore serve as a target for the anabolic treatment of osteoporosis. The exact molecular mechanism by which Sclerostin exerts its antagonistic effects on Wnt signaling in bone forming osteoblasts remains unclear. Here we show that Wnt3a-induced transcriptional responses and induction of alkaline phosphatase activity, an early marker of osteoblast differentiation, require the Wnt co-receptors LRP5 and LRP6. Unlike Dickkopf1 (DKK1), Sclerostin does not inhibit Wnt-3a-induced phosphorylation of LRP5 at serine 1503 or LRP6 at serine 1490. Affinity labeling of cell surface proteins with \([^{125} I]\) Sclerostin identified LRP6 as the main specific Sclerostin receptor in multiple mesenchymal cell lines. When cells were challenged with Sclerostin fused to recombinant green fluorescent protein (GFP) this was internalized, likely via a Clathrin-dependent process, and subsequently degraded in a temperature and proteasome-dependent manner. Ectopic expression of LRP6 greatly enhanced binding and cellular uptake of Sclerostin-GFP, which was reduced by the addition of an excess of non-GFP-fused Sclerostin. Finally, an anti-Sclerostin antibody inhibited the internalization of Sclerostin-GFP and binding of Sclerostin to LRP6. Moreover, this antibody attenuated the antagonistic activity of Sclerostin on canonical Wnt-induced responses.}, language = {en} } @article{TilstamGijbelsHabbeddineetal.2014, author = {Tilstam, Pathricia V. and Gijbels, Marion J. and Habbeddine, Mohamed and Cudejko, Celine and Asare, Yaw and Theelen, Wendy and Zhou, Baixue and D{\"o}ring, Yvonne and Drechsler, Maik and Pawig, Lukas and Simsekyilmaz, Sakine and Koenen, Rory R. and de Winther, Menno P. J. and Lawrence, Toby and Bernhagen, J{\"u}rgen and Zernecke, Alma and Weber, Christian and Noels, Heidi}, title = {Bone Marrow-Specific Knock-In of a Non-Activatable Ikkα Kinase Mutant Influences Haematopoiesis but Not Atherosclerosis in Apoe-Deficient Mice}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0087452}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117450}, pages = {e87452}, year = {2014}, abstract = {Background: The Ikkα kinase, a subunit of the NF-kappa B-activating IKK complex, has emerged as an important regulator of inflammatory gene expression. However, the role of Ikkα-mediated phosphorylation in haematopoiesis and atherogenesis remains unexplored. In this study, we investigated the effect of a bone marrow (BM)-specific activation-resistant Ikk alpha mutant knock-in on haematopoiesis and atherosclerosis in mice. Methods and Results: Apolipoprotein E (Apoe)-deficient mice were transplanted with BM carrying an activation-resistant Ikkα gene (Ikkα(AA/AA) Apoe(-/-)) or with Ikkα(+/+) Apoe(-/-) BM as control and were fed a high-cholesterol diet for 8 or 13 weeks. Interestingly, haematopoietic profiling by flow cytometry revealed a significant decrease in B-cells, regulatory T-cells and effector memory T-cells in Ikkα(AA/AA) Apoe(-/-) BM-chimeras, whereas the naive T-cell population was increased. Surprisingly, no differences were observed in the size, stage or cellular composition of atherosclerotic lesions in the aorta and aortic root of Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) BM-transplanted mice, as shown by histological and immunofluorescent stainings. Necrotic core sizes, apoptosis, and intracellular lipid deposits in aortic root lesions were unaltered. In vitro, BM-derived macrophages from Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) mice did not show significant differences in the uptake of oxidized low-density lipoproteins (oxLDL), and, with the exception of Il-12, the secretion of inflammatory proteins in conditions of Tnf-α or oxLDL stimulation was not significantly altered. Furthermore, serum levels of inflammatory proteins as measured with a cytokine bead array were comparable. Conclusion: Our data reveal an important and previously unrecognized role of haematopoietic Ikkα kinase activation in the homeostasis of B-cells and regulatory T-cells. However, transplantation of Ikkα AA mutant BM did not affect atherosclerosis in Apoe(-/-) mice. This suggests that the diverse functions of Ikkα in haematopoietic cells may counterbalance each other or may not be strong enough to influence atherogenesis, and reveals that targeting haematopoietic Ikkα kinase activity alone does not represent a therapeutic approach.}, language = {en} } @phdthesis{ScheideNoeth2021, author = {Scheide-N{\"o}th, Jan-Philipp}, title = {Activation of the Interleukin-5 receptor and its inhibition by cyclic peptides}, doi = {10.25972/OPUS-18250}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-182504}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The cytokine interleukin-5 (IL-5) is part of the TH2-mediated immune response. As a key regulator of eosinophilic granulocytes (eosinophils), IL-5 controls multiple aspects of eosinophil life. Eosinophils play a pathogenic role in the onset and progression of atopic diseases as well as hypereosinophilic syndrome (HES). Here, cytotoxic proteins and pro-inflammatory mediators stored in intracellular vesicles termed granula are released upon activation thereby causing local inflammation to fight the pathogen. However, if such inflammation persists, tissue damage and organ failure can occur. Due to the close relationship between eosinophils and IL-5 this cytokine has become a major pharmaceutical target for the treatment of atopic diseases or HES. As observed with other cytokines, IL-5 signals by assembling a heterodimeric receptor complex at the cell surface in a stepwise mechanism. In the first step IL-5 binds to its receptor IL-5Rα (CD125). This membrane-located complex then recruits the so-called common beta chain βc (CD131) into a ternary ligand receptor complex, which leads to activation of intracellular signaling cascades. Based on this mechanism various strategies targeting either IL-5 or IL-5Rα have been developed allowing to specifically abrogate IL-5 signaling. In addition to the classical approach of employing neutralizing antibodies against IL 5/IL-5Rα or antagonistic IL-5 variants, two groups comprising small 18 to 30mer peptides have been discovered, that bind to and block IL-5Rα from binding its activating ligand IL-5. Structure-function studies have provided detailed insights into the architecture and interaction of IL-5IL-5Rα and βc. However, structural information for the ternary IL-5 complex as well as IL-5 inhibiting peptides is still lacking. In this thesis three areas were investigated. Firstly, to obtain insights into the second receptor activation step, i.e. formation of the ternary ligand-receptor complex IL-5•IL-5Rα•βc, a high-yield production for the extracellular domain of βc was established to facilitate structure determination of the ternary ligand receptor assembly by either X-ray crystallography or cryo-electron microscopy. In a second project structure analysis of the ectodomain of IL-5Rα in its unbound conformation was attempted. Data on IL-5Rα in its ligand-free state would provide important information as to whether the wrench-like shaped ectodomain of IL-5Rα adopts a fixed preformed conformation or whether it is flexible to adapt to its ligand binding partner upon interaction. While crystallization of free IL-5Rα failed, as the crystals obtained did not diffract X rays to high resolution, functional analysis strongly points towards a selection fit binding mechanism for IL-5Rα instead of a rigid and fixed IL-5Rα structure. Hence IL-5 possibly binds to a partially open architecture, which then closes to the known wrench-like architecture. The latter is then stabilized by interactions within the D1-D2 interface resulting in the tight binding of IL-5. In a third project X-ray structure analysis of a complex of the IL-5 inhibitory peptide AF17121 bound to the ectodomain of IL-5Rα was performed. This novel structure shows how the small cyclic 18mer peptide tightly binds into the wrench-like cleft formed by domains D1 and D2 of IL-5Rα. Due to the partial overlap of its binding site at IL-5Rα with the epitope for IL-5 binding, the peptide blocks IL-5 from access to key residues for binding explaining how the small peptide can effectively compete with the rather large ligand IL-5. While AF17121 and IL-5 seemingly bind to the same site at IL-5Rα, functional studies however showed that recognition and binding of both ligands differ. With the structure for the peptide-receptor complex at hand, peptide design and engineering could be performed to generate AF17121 analogies with enhanced receptor affinity. Several promising positions in the peptide AF17121 could be identified, which could improve inhibition capacity and might serve as a starting point for AF17121-based peptidomimetics that can yield either superior peptide based IL-5 antagonists or small-molecule-based pharmacophores for future therapies of atopic diseases or the hypereosinophilic syndrome.}, subject = {Interleukin 5}, language = {en} } @article{RuckBittnerAfzalietal.2015, author = {Ruck, Tobias and Bittner, Stefan and Afzali, Ali Maisam and G{\"o}bel, Kerstin and Glumm, Sarah and Kraft, Peter and Sommer, Claudia and Kleinschnitz, Christoph and Preusse, Corinna and Stenzel, Werner and Wiendl, Heinz and Meuth, Sven G.}, title = {The NKG2D-IL-15 signaling pathway contributes to T-cell mediated pathology in inflammatory myopathies}, series = {Oncotarget}, volume = {6}, journal = {Oncotarget}, number = {41}, doi = {10.18632/oncotarget.6462}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136047}, year = {2015}, abstract = {NKG2D is an activating receptor on T cells, which has been implicated in the pathogenesis of autoimmune diseases. T cells are critically involved in idiopathic inflammatory myopathies (IIM) and have been proposed as specific therapeutic targets. However, the mechanisms underlying T cell-mediated progressive muscle destruction in IIM remain to be elucidated. We here determined the involvement of the NKG2D - IL-15 signaling pathway. Primary human myoblasts expressed NKG2D ligands, which were further upregulated upon inflammatory stimuli. In parallel, shedding of the soluble NKG2D ligand MICA (sMICA) decreased upon inflammation potentially diminishing inhibition of NKG2D signaling. Membrane-related expression of IL-15 by myoblasts induced differentiation of naive CD8\(^+\) T cells into highly activated, cytotoxic \(CD8^+NKG2D^{high}\) T cells demonstrating NKG2D-dependent lysis of myoblasts in vitro. \(CD8^+NKG2D^{high}\) T cell frequencies were increased in the peripheral blood of polymyositis (PM) patients and correlated with serum creatinine kinase concentrations, while serum sMICA levels were not significantly changed. In muscle biopsy specimens from PM patients expression of the NKG2D ligand MICA/B was upregulated, IL-15 was expressed by muscle cells, CD68\(^+\) macrophages as well as CD4\(^+\) T cells, and \(CD8^+NKG2D^+\) cells were frequently detected within inflammatory infiltrates arguing for a local signaling circuit in the inflammatory muscle milieu. In conclusion, the NKG2D - IL-15 signaling pathway contributes to progressive muscle destruction in IIM potentially opening new therapeutic avenues.}, language = {en} } @phdthesis{Plochmann2011, author = {Plochmann, Kathrin}, title = {Bioassays zur Untersuchung der biologischen Aktivit{\"a}t von Flavonoiden und Ermittlung eines zellul{\"a}ren Rezeptormolek{\"u}ls von foamyviralen Vektoren}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65183}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Aufgrund ihrer gut dokumentierten, umfangreichen gesundheitsf{\"o}rdernden biologischen Aktivit{\"a}ten wird den Flavonoiden eine große Bedeutung zugeordnet. Die Ergebnisse von in vitro- und Tierstudien deuten zudem darauf hin, dass diese Verbindungen bei der Pr{\"a}vention und Therapie von Erkrankungen wie Krebs oder Alzheimer Krankheit (AD) positive Effekte zeigen. Zur besseren Charakterisierung der Interaktion von Flavonoiden mit Krebszellen wurden von uns die Cytotoxizit{\"a}t verschiedener Flavonoide auf T-Lymphoblastomzellen untersucht und Strukturelemente identifiziert, welche f{\"u}r einen Flavonoid-induzierten Zelltod relevant sind. Weitere Studien waren der potentiell neuroprotektiven Wirkung von Flavonoiden gewidmet. Die sowohl in neuronalen Zellkulturen als auch in transgenen Alzheimer-M{\"a}usen (TgAPPsw) festgestellte Erh{\"o}hung der sAPPα Produktion und Reduktion von Aβ-Bildung wurden mit Aktivit{\"a}ts- und Expressionssteigerung der α-Sekretase ADAM-10 assoziiert. Um herauszufinden, ob Flavonoide eine neuroprotektive Wirkung zeigen, wurden erste Vorbereitungen f{\"u}r ein Flavonoid-Screening mit einer sowohl hAPP alsauch ADAM-10 stabil transfizierten HT1080 Zellen getroffen. Dies beinhaltete die Suche nach einer potenten siRNA/shRNA und einem effektiven Flavonoid. Im zweiten Teil der Arbeit wurden Experimente durchgef{\"u}hrt, um die Rolle von Heparansulfat (HS) bei der foamyviralen Anbindung an die Wirtszelle zu untersuchen. Foamyviren (FV) sind Spumaviren und geh{\"o}ren zur Familie der Retroviren. Bei unseren Studien wurde die Bindung von FV an Heparin, die Korrelation der Suszeptibilit{\"a}t verschiedener Zellen mit zellul{\"a}rem HS und die Reduktion der Infektion durch l{\"o}sliches Heparin sowie durch enzymatischen HS-Abbau festgestellt.}, subject = {Flavonoide}, language = {de} } @article{PilsKoppPetersonetal.2012, author = {Pils, Stefan and Kopp, Kathrin and Peterson, Lisa and Tascon, Julia Delgado and Nyffenegger-Jann, Naja J. and Hauck, Christof R.}, title = {The Adaptor Molecule Nck Localizes the WAVE Complex to Promote Actin Polymerization during CEACAM3-Mediated Phagocytosis of Bacteria}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {3}, doi = {10.1371/journal.pone.0032808}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131747}, pages = {e32808}, year = {2012}, abstract = {Background: CEACAM3 is a granulocyte receptor mediating the opsonin-independent recognition and phagocytosis of human-restricted CEACAM-binding bacteria. CEACAM3 function depends on an intracellular immunoreceptor tyrosine-based activation motif (ITAM)-like sequence that is tyrosine phosphorylated by Src family kinases upon receptor engagement. The phosphorylated ITAM-like sequence triggers GTP-loading of Rac by directly associating with the guanine nucleotide exchange factor (GEF) Vav. Rac stimulation in turn is critical for actin cytoskeleton rearrangements that generate lamellipodial protrusions and lead to bacterial uptake. Principal Findings: In our present study we provide biochemical and microscopic evidence that the adaptor proteins Nck1 and Nck2, but not CrkL, Grb2 or SLP-76, bind to tyrosine phosphorylated CEACAM3. The association is phosphorylation-dependent and requires the Nck SH2 domain. Overexpression of the isolated Nck1 SH2 domain, RNAi-mediated knock-down of Nck1, or genetic deletion of Nck1 and Nck2 interfere with CEACAM3-mediated bacterial internalization and with the formation of lamellipodial protrusions. Nck is constitutively associated with WAVE2 and directs the actin nucleation promoting WAVE complex to tyrosine phosphorylated CEACAM3. In turn, dominant-negative WAVE2 as well as shRNA-mediated knock-down of WAVE2 or the WAVE-complex component Nap1 reduce internalization of bacteria. Conclusions: Our results provide novel mechanistic insight into CEACAM3-initiated phagocytosis. We suggest that the CEACAM3 ITAM-like sequence is optimized to co-ordinate a minimal set of cellular factors needed to efficiently trigger actin-based lamellipodial protrusions and rapid pathogen engulfment.}, language = {en} } @article{PerkovicAgarwalFiorettoetal.2016, author = {Perkovic, Vlado and Agarwal, Rajiv and Fioretto, Paola and Hemmelgarn, Brenda R. and Levin, Adeera and Thomas, Merlin C. and Wanner, Christoph and Kasiske, Bertram L. and Wheeler, David C. and Groop, Per-Henrik}, title = {Management of patients with diabetes and CKD: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) controversies conference}, series = {Kidney International}, volume = {90}, journal = {Kidney International}, number = {6}, doi = {10.1016/j.kint.2016.09.010}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186599}, pages = {1175-1183}, year = {2016}, abstract = {The prevalence of diabetes around the world has reached epidemic proportions and is projected to increase to 642 million people by 2040. Diabetes is already the leading cause of end-stage kidney disease (ESKD) in most developed countries, and the growth in the number of people with ESKD around the world parallels the increase in diabetes. The presence of kidney disease is associated with a markedly elevated risk of cardiovascular disease and death in people with diabetes. Several new therapies and novel investigational agents targeting chronic kidney disease patients with diabetes are now under development. This conference was convened to assess our current state of knowledge regarding optimal glycemic control, current antidiabetic agents and their safety, and new therapies being developed to improve kidney function and cardiovascular outcomes for this vulnerable population.}, language = {en} } @phdthesis{Noskov2003, author = {Noskov, Andrey}, title = {Structural and functional studies of the Interleukin-5 receptor system}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-8195}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {The aim of current work was contribution to the long-term ongoing project on developing human IL-5 agonists/antagonists that intervene with or inhibit IL-5 numerous functions in cell culture and/or in animal disease models. To facilitate design of an IL-5 antagonist variant or low-molecular weight mimetics only capable of binding to the specific receptor alpha chain, but would lack the ability to attract the receptor common \&\#946;-chain and thus initiate receptor complex activation it is necessary to gain the information on minimal structural and functional epitopes. Such a strategy was successfully adopted in our group on example of Interleukin 4. To precisely localize minimal structural epitope it is essential to have structure of the ligand in its bound form and especially informative would be structure of complex of the ligand and its specific receptor alpha chain. For this purpose large quantities (tens of milligrams), retaining full biological activity IL-5 and extracellular domain of IL-5 specific receptor \&\#945;-chain were expressed in a bacterial expression system (E.coli). After successful refolding proteins were purified to 95-99\% Stable and soluble receptor:ligand complex was prepared. Each established purification and refolding procedures were subjected to optimization targeting maximal yields and purity. Produced receptor:ligand complex was applied to crystallization experiments. Microcrystals were initially obtained with a flexible sparse matrix screening methodology. Crystal quality was subsequently improved by fine-tuning of the crystallization conditions. At this stage crystals of about 800x150x30µm in size can be obtained. They possess desirable visible characteristics of crystals including optical clarity, smooth facecs and sharp edges. Crystals rotate plane polarized light reflecting their well internal organization. Unfortunately relative slimness and sometimes cluster nature of the produced crystals complicates acquisition of high-resolution dataset and resolution of the structure. With some of obtained crystals diffraction to a resolution up to 4{\AA} was observed.}, subject = {Interleukin 5}, language = {en} } @article{MilanosElsharifJanzenetal.2017, author = {Milanos, Sinem and Elsharif, Shaimaa A. and Janzen, Dieter and Buettner, Andrea and Villmann, Carmen}, title = {Metabolic Products of Linalool and Modulation of GABA\(_{A}\) Receptors}, series = {Frontiers in Chemistry}, volume = {5}, journal = {Frontiers in Chemistry}, number = {46}, doi = {10.3389/fchem.2017.00046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170779}, year = {2017}, abstract = {Terpenoids are major subcomponents in aroma substances which harbor sedative physiological potential. We have demonstrated that various monoterpenoids such as the acyclic linalool enhance GABAergic currents in an allosteric manner in vitro upon overexpression of inhibitory α1β2 GABA\(_{A}\) receptors in various expression systems. However, in plants or humans, i.e., following intake via inhalation or ingestion, linalool undergoes metabolic modifications including oxygenation and acetylation, which may affect the modulatory efficacy of the generated linalool derivatives. Here, we analyzed the modulatory potential of linalool derivatives at α1β2γ2 GABA\(_{A}\) receptors upon transient overexpression. Following receptor expression control, electrophysiological recordings in a whole cell configuration were used to determine the chloride influx upon co-application of GABA EC\(_{10-30}\) together with the modulatory substance. Our results show that only oxygenated linalool metabolites at carbon 8 positively affect GABAergic currents whereas derivatives hydroxylated or carboxylated at carbon 8 were rather ineffective. Acetylated linalool derivatives resulted in non-significant changes of GABAergic currents. We can conclude that metabolism of linalool reduces its positive allosteric potential at GABAA receptors compared to the significant potentiation effects of the parent molecule linalool itself.}, language = {en} }