Opazo Davila, Luis Felipe

[["dc.bibliographiccitation.firstpage","26349"],["dc.bibliographiccitation.issue","46"],["dc.bibliographiccitation.journal","Physical Chemistry Chemical Physics"],["dc.bibliographiccitation.lastpage","26355"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Saul, Philip"],["dc.contributor.author","Yang, Shengjun"],["dc.contributor.author","Mamone, Salvatore"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Meyer, Andreas"],["dc.contributor.author","Rizzoli, Silvio O."],["dc.contributor.author","Glöggler, Stefan"],["dc.date.accessioned","2021-12-01T09:20:55Z"],["dc.date.available","2021-12-01T09:20:55Z"],["dc.date.issued","2021"],["dc.description.abstract","Dendrimers display an exotic spin state behavior that we propose to tune for ion sensing."],["dc.description.abstract","Dendrimers are a class of branched, highly symmetric macromolecules that have been shown to be useful for a vast number of different applications. Potential uses as fluorescence sensors, in catalysis and perhaps most importantly in medical applications as drug delivery systems or cytotoxica have been proposed. Herein we report on an exotic behaviour of the nuclear spins in a dendritic macromolecule in the presence of different paramagnetic ions. We show that the stability of the long lived nuclear singlet state, is affected by the presence of Cu( ii ), whereas other ions did not have any influence at all. This effect could not be observed in the case of a simple tripeptide, in which the nuclear singlet stability was influenced by all investigated paramagnetic ions, a potentially useful effect in the development of Cu( ii ) selective probes. By adding a fluorescent marker to our molecule we could show that the nuclear singlet multimer (NUSIMER) is taken up by living cells. Furthermore we were able to show that nuclear singlet state NMR can be used to investigate the NUSIMER in the presence of living cells, showing that an application in in vivo NMR can be feasible."],["dc.description.abstract","Dendrimers display an exotic spin state behavior that we propose to tune for ion sensing."],["dc.description.abstract","Dendrimers are a class of branched, highly symmetric macromolecules that have been shown to be useful for a vast number of different applications. Potential uses as fluorescence sensors, in catalysis and perhaps most importantly in medical applications as drug delivery systems or cytotoxica have been proposed. Herein we report on an exotic behaviour of the nuclear spins in a dendritic macromolecule in the presence of different paramagnetic ions. We show that the stability of the long lived nuclear singlet state, is affected by the presence of Cu( ii ), whereas other ions did not have any influence at all. This effect could not be observed in the case of a simple tripeptide, in which the nuclear singlet stability was influenced by all investigated paramagnetic ions, a potentially useful effect in the development of Cu( ii ) selective probes. By adding a fluorescent marker to our molecule we could show that the nuclear singlet multimer (NUSIMER) is taken up by living cells. Furthermore we were able to show that nuclear singlet state NMR can be used to investigate the NUSIMER in the presence of living cells, showing that an application in in vivo NMR can be feasible."],["dc.identifier.doi","10.1039/D1CP04483D"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/94301"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-478"],["dc.relation.eissn","1463-9084"],["dc.relation.issn","1463-9076"],["dc.rights.uri","http://creativecommons.org/licenses/by/3.0/"],["dc.title","Exotic nuclear spin behavior in dendritic macromolecules"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","13221"],["dc.bibliographiccitation.issue","67"],["dc.bibliographiccitation.journal","Chemical Communications"],["dc.bibliographiccitation.lastpage","13224"],["dc.bibliographiccitation.volume","51"],["dc.contributor.author","Kabatas, Selda"],["dc.contributor.author","Vreja, Ingrid C."],["dc.contributor.author","Saka, Sinem K."],["dc.contributor.author","Hoeschen, Carmen"],["dc.contributor.author","Kroehnert, Katharina"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Rizzoli, S. O."],["dc.contributor.author","Diederichsen, Ulf"],["dc.date.accessioned","2017-09-07T11:44:43Z"],["dc.date.available","2017-09-07T11:44:43Z"],["dc.date.issued","2015"],["dc.description.abstract","Imaging techniques should differentiate between specific signals, from the biomolecules of interest, and non-specific signals, from the background. We present a probe containing N-15 and N-14 isotopes in approximately equal proportion, for secondary ion mass spectrometry imaging. This probe designed for a precise biomolecule analysis is insensitive to background signals."],["dc.identifier.doi","10.1039/c5cc03895b"],["dc.identifier.gro","3141979"],["dc.identifier.isi","000359246500017"],["dc.identifier.pmid","26195041"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/3201"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1364-548X"],["dc.relation.issn","1359-7345"],["dc.title","A contamination-insensitive probe for imaging specific biomolecules by secondary ion mass spectrometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","427"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Communicative & Integrative Biology"],["dc.bibliographiccitation.lastpage","429"],["dc.bibliographiccitation.volume","3"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Rizzoli, S. O."],["dc.date.accessioned","2017-09-07T11:54:04Z"],["dc.date.available","2017-09-07T11:54:04Z"],["dc.date.issued","2010"],["dc.description.abstract","Neurotransmitter release relies on the fusion of synaptic vesicles with the plasma membrane of synaptic boutons, which is followed by the recycling of vesicle components and formation of new vesicles. It is not yet clear whether upon fusion the vesicles persist as multimolecular patches in the plasma membrane, or whether they segregate into individual components. Evidence supporting each of these two models has been suggested in recent years. Using diffraction-unlimited imaging (stimulated emission depletion, or STED) of native synaptic vesicle proteins, we have proposed that vesicle proteins remain in clusters on the neuronal surface. These clusters do not appear to intermix. We discuss here these findings in the context of previous studies on synaptic vesicle fusion, and we propose a recycling model which accounts for most of the recent findings on the post-fusion fate of synaptic vesicle components."],["dc.identifier.doi","10.4161/cib.3.5.12132"],["dc.identifier.gro","3145094"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2793"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.status","final"],["dc.relation.issn","1942-0889"],["dc.title","The fate of synaptic vesicle components upon fusion"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4744"],["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","The Analyst"],["dc.bibliographiccitation.lastpage","4747"],["dc.bibliographiccitation.volume","146"],["dc.contributor.author","Glowacki, Selda Kabatas"],["dc.contributor.author","Gomes de Castro, Maria Angela"],["dc.contributor.author","Yip, Ka Man"],["dc.contributor.author","Asadpour, Ommolbanin"],["dc.contributor.author","Münchhalfen, Matthias"],["dc.contributor.author","Engels, Niklas"],["dc.contributor.author","Opazo, Felipe"],["dc.date.accessioned","2021-08-12T07:45:03Z"],["dc.date.available","2021-08-12T07:45:03Z"],["dc.date.issued","2021"],["dc.description.abstract","Monovalent NIP probes for studying B cell antigen receptors in fluorescence-based techniques, including diffraction unlimited microscopy."],["dc.description.abstract","We have developed a series of monovalent fluorophore-conjugated affinity probes based on the hapten 3-nitro-4-hydroxy-5-iodophenylacetyl (NIP), which is widely used as a model antigen to study B lymphocytes and the functional principles of B cell antigen receptors (BCRs). We successfully used them in flow-cytometry, confocal and super-resolution microscopy techniques."],["dc.description.abstract","Monovalent NIP probes for studying B cell antigen receptors in fluorescence-based techniques, including diffraction unlimited microscopy."],["dc.description.abstract","We have developed a series of monovalent fluorophore-conjugated affinity probes based on the hapten 3-nitro-4-hydroxy-5-iodophenylacetyl (NIP), which is widely used as a model antigen to study B lymphocytes and the functional principles of B cell antigen receptors (BCRs). We successfully used them in flow-cytometry, confocal and super-resolution microscopy techniques."],["dc.identifier.doi","10.1039/D1AN00601K"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/88359"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-448"],["dc.relation.eissn","1364-5528"],["dc.relation.issn","0003-2654"],["dc.title","A fluorescent probe for STED microscopy to study NIP-specific B cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e21"],["dc.bibliographiccitation.journal","Molecular Therapy — Nucleic Acids"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Wilner, Samantha E."],["dc.contributor.author","Wengerter, Brian"],["dc.contributor.author","Maier, Keith"],["dc.contributor.author","Borba Magalhaes, Maria de Lourdes"],["dc.contributor.author","Amo, David Soriano del"],["dc.contributor.author","Pai, Supriya"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Rizzoli, S. O."],["dc.contributor.author","Yan, Amy"],["dc.contributor.author","Levy, Matthew"],["dc.date.accessioned","2017-09-07T11:48:53Z"],["dc.date.available","2017-09-07T11:48:53Z"],["dc.date.issued","2012"],["dc.description.abstract","The transferrin receptor, CD71, is an attractive target for drug development because of its high expression on a number of cancer cell lines and the blood brain barrier. To generate serum-stabilized aptamers that recognize the human transferrin receptor, we have modified the traditional aptamer selection protocol by employing a functional selection step that enriches for RNA molecules which bind the target receptor and are internalized by cells. Selected aptamers were specific for the human receptor, rapidly endocytosed by cells and shared a common core structure. A minimized variant was found to compete with the natural ligand, transferrin, for receptor binding and cell uptake, but performed similar to twofold better than it in competition experiments. Using this molecule, we generated aptamer-targeted siRNA-laden liposomes. Aptamer targeting enhanced both uptake and target gene knockdown in cells grown in culture when compared to nonmodified or nontargeted liposomes. The aptamer should prove useful as a surrogate for transferrin in many applications including cell imaging and targeted drug delivery."],["dc.identifier.doi","10.1038/mtna.2012.14"],["dc.identifier.gro","3142542"],["dc.identifier.isi","000208875500001"],["dc.identifier.pmid","23344001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8904"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","2162-2531"],["dc.title","An RNA Alternative to Human Transferrin: A New Tool for Targeting Human Cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","436"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","BioEssays"],["dc.bibliographiccitation.lastpage","451"],["dc.bibliographiccitation.volume","37"],["dc.contributor.author","Fornasiero, Eugenio F."],["dc.contributor.author","Opazo, Felipe"],["dc.date.accessioned","2018-11-07T09:59:15Z"],["dc.date.available","2018-11-07T09:59:15Z"],["dc.date.issued","2015"],["dc.description.abstract","The recent 2014 Nobel Prize in chemistry honored an era of discoveries and technical advancements in the field of super-resolution microscopy. However, the applications of diffraction-unlimited imaging in biology have a long road ahead and persistently engage scientists with new challenges. Some of the bottlenecks that restrain the dissemination of super-resolution techniques are tangible, and include the limited performance of affinity probes and the yet not capillary diffusion of imaging setups. Likewise, super-resolution microscopy has introduced new paradigms in the design of projects that require imaging with nanometer-resolution and in the interpretation of biological images. Besides structural or morphological characterization, super-resolution imaging is quickly expanding towards interaction mapping, multiple target detection and live imaging. Here we review the recent progress of biologists employing super-resolution imaging, some pitfalls, implications and new trends, with the purpose of animating the field and spurring future developments."],["dc.identifier.doi","10.1002/bies.201400170"],["dc.identifier.isi","000351546000013"],["dc.identifier.pmid","25581819"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37549"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1521-1878"],["dc.relation.issn","0265-9247"],["dc.title","Super-resolution imaging for cell biologists Concepts, applications, current challenges and developments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","19055"],["dc.bibliographiccitation.issue","44"],["dc.bibliographiccitation.journal","Proceedings of the National Academy of Sciences of the United States of America"],["dc.bibliographiccitation.lastpage","19060"],["dc.bibliographiccitation.volume","107"],["dc.contributor.author","Hoopmann, Peer"],["dc.contributor.author","Punge, Annedore"],["dc.contributor.author","Barysch, Sina Victoria"],["dc.contributor.author","Westphal, Volker"],["dc.contributor.author","Bückers, Johanna"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Bethani, Ioanna"],["dc.contributor.author","Lauterbach, Marcel A."],["dc.contributor.author","Hell, Stefan"],["dc.contributor.author","Rizzoli, Silvio"],["dc.date.accessioned","2017-09-07T11:45:12Z"],["dc.date.available","2017-09-07T11:45:12Z"],["dc.date.issued","2010"],["dc.description.abstract","Neurotransmitter release is achieved through the fusion of synaptic vesicles with the neuronal plasma membrane (exocytosis). Vesicles are then retrieved from the plasma membrane (endocytosis). It was hypothesized more than 3 decades ago that endosomes participate in vesicle recycling, constituting a slow endocytosis pathway required especially after prolonged stimulation. This recycling model predicts that newly endocytosed vesicles fuse with an endosome, which sorts (organizes) the molecules and buds exocytosis-competent vesicles. We analyzed here the endosome function using hippocampal neurons, isolated nerve terminals (synaptosomes), and PC12 cells by stimulated emission depletion microscopy, photooxidation EM, and several conventional microscopy assays. Surprisingly, we found that endosomal sorting is a rapid pathway, which appeared to be involved in the recycling of the initial vesicles to be released on stimulation, the readily releasable pool. In agreement with the endosomal model, the vesicle composition changed after endocytosis, with the newly formed vesicles being enriched in plasma membrane proteins. Vesicle proteins were organized in clusters both in the plasma membrane (on exocytosis) and in the endosome. In the latter compartment, they segregated from plasma membrane components in a process that is likely important for sorting/budding of newly developed vesicles from the endosome."],["dc.identifier.doi","10.1073/pnas.1007037107"],["dc.identifier.gro","3142833"],["dc.identifier.isi","000283749000058"],["dc.identifier.pmid","20956291"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/281"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0027-8424"],["dc.title","Endosomal sorting of readily releasable synaptic vesicles"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","269"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Biomolecules"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Kilisch, Markus"],["dc.contributor.author","Götzke, Hansjörg"],["dc.contributor.author","Gere-Becker, Maja"],["dc.contributor.author","Crauel, Alexander"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Frey, Steffen"],["dc.date.accessioned","2021-04-14T08:29:47Z"],["dc.date.available","2021-04-14T08:29:47Z"],["dc.date.issued","2021"],["dc.identifier.doi","10.3390/biom11020269"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82990"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","2218-273X"],["dc.title","Discovery and Characterization of an ALFA-Tag-Specific Affinity Resin Optimized for Protein Purification at Low Temperatures in Physiological Buffer"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","461"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Molecular Microbiology"],["dc.bibliographiccitation.lastpage","477"],["dc.bibliographiccitation.volume","71"],["dc.contributor.author","Iliev, Asparouh I."],["dc.contributor.author","Djannatian, Jasmin Roya"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Gerber, Joachim"],["dc.contributor.author","Nau, Roland"],["dc.contributor.author","Mitchell, Timothy J."],["dc.contributor.author","Wouters, Fred S."],["dc.date.accessioned","2018-11-07T08:35:08Z"],["dc.date.available","2018-11-07T08:35:08Z"],["dc.date.issued","2009"],["dc.description.abstract","Streptococcus pneumoniae is the most frequent cause of bacterial meningitis, leading to permanent neurological damage in 30% and lethal outcome in 25% of patients. The cholesterol-dependent cytolysin pneumolysin is a major virulence factor of S. pneumoniae. It produces rapid cell lysis at higher concentrations or apoptosis at lower concentrations. Here, we show that sublytic amounts of pneumolysin produce rapid bundling and increased acetylation of microtubules (signs of excessive microtubule stabilization) in various types of cells - neuroblastoma cells, fibroblasts and primary astrocytes. The bundling started perinuclearly and extended peripherally towards the membrane. The effect was not connected to pneumolysin's capacity to mediate calcium influx, macropore formation, apoptosis, or RhoA and Rac1 activation. Cellular cholesterol depletion and neutralization of the toxin by pre-incubation with cholesterol completely inhibited the microtubule phenotype. Pharmacological inhibition of Src-family kinases diminished microtubule bundling, suggesting their involvement in the process. The relevance of microtubule stabilization to meningitis was confirmed in an experimental pneumococcal meningitis animal model, where increased acetylation was observed. Live imaging experiments demonstrated a decrease in organelle motility after toxin challenge in a manner comparable to the microtubule-stabilizing agent taxol, thus proposing a possible pathogenic mechanism that might contribute to the CNS damage in pneumococcal meningitis."],["dc.identifier.doi","10.1111/j.1365-2958.2008.06538.x"],["dc.identifier.isi","000262304400014"],["dc.identifier.pmid","19040644"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17989"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell Publishing, Inc"],["dc.relation.issn","0950-382X"],["dc.title","Rapid microtubule bundling and stabilization by the Streptococcus pneumoniae neurotoxin pneumolysin in a cholesterol-dependent, non-lytic and Src-kinase dependent manner inhibits intracellular trafficking"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","36"],["dc.bibliographiccitation.journal","Journal of Visualized Experiments"],["dc.contributor.author","Opazo, Felipe"],["dc.contributor.author","Rizzoli, S. O."],["dc.date.accessioned","2017-09-07T11:54:04Z"],["dc.date.available","2017-09-07T11:54:04Z"],["dc.date.issued","2010"],["dc.description.abstract","The fusion of synaptic vesicles with the plasma membrane (exocytosis) is a required step in neurotransmitter release and neuronal communication. The vesicles are then retrieved from the plasma membrane (endocytosis) and grouped together with the general pool of vesicles within the nerve terminal, until they undergo a new exo- and endocytosis cycle (vesicle recycling). These processes have been studied using a variety of techniques such as electron microscopy, electrophysiology recordings, amperometry and capacitance measurements. Importantly, during the last two decades a number of fluorescently labeled markers emerged, allowing optical techniques to track vesicles in their recycling dynamics. One of the most commonly used markers is the styryl or FM dye; structurally, all FM dyes contain a hydrophilic head and a lipophilic tail connected through an aromatic ring and one or more double bonds (Fig. 1B). A classical FM dye experiment to label a pool of vesicles consists in bathing the preparation (Fig. 1Ai) with the dye during the stimulation of the nerve (electrically or with high K(+)). This induces vesicle recycling and the subsequent loading of the dye into recently endocytosed vesicles (Fig. 1A(i-iii;)). After loading the vesicles with dye, a second round of stimulation in a dye-free bath would trigger the FM release through exocytosis (Fig. 1A(iv-v;)), process that can be followed by monitoring the fluorescence intensity decrease (destaining). Although FM dyes have contributed greatly to the field of vesicle recycling, it is not possible to determine the exact localization or morphology of individual vesicles by using conventional fluorescence microscopy. For that reason, we explain here how FM dyes can also be used as endocytic markers using electron microscopy, through photoconversion. The photoconversion technique exploits the property of fluorescent dyes to generate reactive oxygen species under intense illumination. Fluorescently labeled preparations are submerged in a solution containing diaminobenzidine (DAB) and illuminated. Reactive species generated by the dye molecules oxidize the DAB, which forms a stable, insoluble precipitate that has a dark appearance and can be easily distinguished in electron microscopy. As DAB is only oxidized in the immediate vicinity of fluorescent molecules (as the reactive oxygen species are short-lived), the technique ensures that only fluorescently labeled structures are going to contain the electron-dense precipitate. The technique thus allows the study of the exact location and morphology of actively recycling organelles."],["dc.identifier.doi","10.3791/1790"],["dc.identifier.gro","3145095"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2794"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.status","final"],["dc.relation.issn","1940-087X"],["dc.title","Studying Synaptic Vesicle Pools using Photoconversion of Styryl Dyes"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]