Wo: Hörsaal C1 im Chemikum, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen
Wann: Donnerstags um 17:00
Termine im SS 2018:
12.04.2018: Prof. Dr. Christoph Lambert, Universität Würzburg, Thema „Can magnetic fields influence chemical reactions? About charlatans and electron spins“
Abstract: Magnetic fields interact with matter in various ways and are often believed to be either dangerous to human beings or may heal several illnesses. But can magnetic fields really influence physiological processes, that is, chemical reactions? This talk will give insight into the mechanisms of magnetic field effects (MFE) in chemistry and present examples how the MFE act in charge separated radical pairs. These spin-correlated radical pairs are formed by photoinduced electron transfer processes in molecular triads consisting of an electron donor, a transition metal complex photosensitizer, and an electron acceptor
26.04.2018: Prof. Oliver Seitz, Humboldt-Universität zu Berlin, Thema „Imaging and Hijacking of RNA“
Abstract: A current challenge in the field is the imaging and quantification of specific RNA molecules in live cells. We have introduced the FIT-Probes, i.e. quencher-free hybridization probes which contain a single asymmetric cyanine dye that serves as a fluorescent base surrogate. The ‘dye base’ acts as a local intercalator probe and reports hybridization. The combination with additional dyes and/or the introduction of a local constraint in the vicinity of the ‘dye base’ enables designs which provide exceptional brightness and quantitative imaging of RNA. I will show that Enhanced FIT-Probes enable the imaging of the dynamics of small, oskar mRNA containing ribonucleotide particles in developing Drosophila melanogaster oocytes and of small viral RNA upon Influenza infection. Recently, we extended the color repertoire of DNA FIT probes. I will discuss the prospects for imaging of single nucleotide alterations introduced in cells upon mRNA C→U editing.
DNA and RNA are informational molecules. I will show how the information encoded in DNA/RNA can be hijacked. We consider nucleic acid molecules as templates that provide unique opportunities for the controlled presentation of functional units. For example, the controlled presentation of peptides on antisense compounds provides opportunities for enhancing cytotoxicity by perturbation of select protein-protein interactions. Nucleic acids can be used as templates that trigger chemical reactions. We explore whether RNA templated reactions can be used for the design of molecular doctors, which initiate the synthesis of drug-like compounds only in those cells expressing particular RNA sequences.
 F. Hövelmann, O. Seitz, Acc. Chem. Res. 2016, 49, 714;  I. Gaspar, F. Hövelmann, J. Chamiolo, A. Ephrussi, O. Seitz, ACS Chem. Biol. 2018, 13, 742;  a) F. Hövelmann, I. Gaspar, S. Loibl, E.A. Ermilov, B. Röder, A. Ephrussi, O. Seitz, Angew. Chem. Int. Ed. 2014, 53, 11370; b) I. Haralampiev, M. Schade, J. Chamiolo, F. Jolmes, S. Prisner, P.T. Witkowski, M. Behrent, F. Hövelmann, T. Wolff, O. Seitz, A. Herrmann, ChemBioChem 2017, 18, 1589;  F. Hövelmann, I. Gaspar, J. Chamiolo, M. Kasper, J. Steffen, A. Ephrussi, O. Seitz, Chem.Sci 2016, 7, 128;  V. Bandlow, S. Liese, D. Lauster, K. Ludwig, R.R. Netz, A. Herrmann, O. Seitz, J. Am. Chem. Soc. 2017, 139, 16389;  F. Abendroth, O. Seitz, Angew. Chem. Int. Ed. 2014, 53, 10504;  M. Di Pisa, A. Hauser, O. Seitz, ChemBioChem 2017, 18, 872.
17.05.2018: PD Dr. Felix Zelder, University of Zürich, Thema „Chemistry, Biomimetic Studies and Applications with Vitamin B12 Derivatives and Related Macrocycles“
Abstract: Cobalamins (Cbls) play important roles as enzymatic cofactors, photoreceptors and allosteric effectors in biological systems. In Cbl-protein and Cbl-nucleic acid complexes, biological function is often controlled by unique structural features of the organometallic cobalt-containing corrin macrocycles. My group develops modified B12 derivatives and related macrocycles for fundamental studies, analytical purposes and potential medicinal applications. Recently, we developed an immobilisation strategy for mimicking an important proton relay mechanism in cofactor-B12 protein complexes. In other studies, we focus on developing B12 derivatives as inhibitors of bacterial and cancer cells growth. In our analytical chemistry program, we develop metal-complexes for detecting small molecules and ions in competitive biological media.
 J. Bridwell-Raab, C. L. Drennan, Curr. Opin. Chem. Biol. 2017, 37, 63-70;  F. Zelder, Chem. Commun. 2015, 51, 14004-14017;  M. Sonnay, T. Fox, O. Blacque, F. Zelder, Chem. Sci. 2016, 7, 3836-3842;  N. Kumari, F. Zelder, Chem. Commun. 2015, 51, 17170-17173.
07.06.2018: Prof. Beate Koksch, Freie Universität Berlin, Thema „Fluorine in Peptide and Protein Engineering“
Abstract: In a league of its own, fluorine has the potential to enable us to engineer biopolymers with highly desirable properties. However, the particular challenge in using it as a tool lies in our ability to juggle the interplay between the specific properties of the fluorinated building block and its responsiveness to the environment it is exposed to.
Fluorine has been shown to impart often favorable but seldom predictable properties to peptides and proteins, a phenomenon that is caused by the nature of the fluorine atom and properties of the C-F bond. Up until about two decades ago, the outcomes of fluorine modification of peptides and proteins were largely left to chance. Driven by the motivation to extend the application of the unique properties of the element fluorine from medicinal and agro chemistry to peptide and protein engineering we have established multiple peptide and protein models with different properties for the purpose of studying the consequences of fluorine substitution in the context of a protein environment.
In general, the consequences of incorporating the C-F bond into a biopolymer can be attributed to two distinct yet related phenomena: 1) the fluorine substituent can directly engage in intermolecular interactions with its environment and/or 2) the other functional groups present in the molecule can be influenced by the electron withdrawing nature of this element (intramolecular) and in turn interact differently with their immediate environment (intermolecular). Also, we could show that not only the nature of the side chain but also its immediate environment determine the outcome of this substitution.
We have especially been fascinated to observe that the difference of as subtle as one fluorine atom in the side chain of an amino acid can dramatically influence the key properties of peptides and proteins such as hydrophobicity, polarity and secondary structure propensity. These properties are crucial factors in peptide and protein engineering as they direct properties as important as proteolytic stability and folding, and thus affect protein function. One of our current projects studies the way in which not just biomolecules in the laboratory, but whole living organisms accommodate fluorine and this talk will introduce our first results of this endeavor.
A.A. Berger, J.-S. Völler, N. Budisa, B. Koksch. Acc. Chem. Res. 2017, 50 (9), 2093-2103; Völler, M. Dulic, U. Gerling-Driessen, H. Biava, T. Baumann, N. Budisa, I. Gruic-Sovuli, B. Koksch. ACS Central Science 2017, 3 (1), 73–80; Ye, B. Loll, A.A. Berger, U. Mülow, C. Alings, M. Wahl, B. Koksch. Chem. Sci. 2015, 6, 5246 – 5254; U.I.M. Gerling, M. Salwiczek, C.D. Cadicamo, H. Erdbrink, S. Grage, P. Wadhwani, A. Ulrich, M. Behrens, G. Haufe, C. Czekelius, B. Koksch. Chem. Sci. 2014, 5 (2), 819-830; Nyakatura, O. Reimann, T. Vagt, M. Salwiczek, B. Koksch. RSC Advances 2013, 3 (18), 6319 – 6322; Salwiczek, E.K. Nyakatura, U.I.M. Gerling, S. Ye, B. Koksch. Chem.Soc.Rev. 2012, 41 (6), 2135 – 2171; Salwiczek, S. Samsonov, T. Vagt, C. Baldauf, E. Nyakatura, E. Fleige, J. Numata, H. Cölfen, M. T. Pisabarro, B. Koksch. Chem. Eur. J. 2009, 15 (31,) 7628-7636; C. Jäckel, M. Salwiczek, B. Koksch. Angew. Chem. Int. Ed., 2006, 45, 4198-4203
21.06.2018: Prof. Roger Alberto, University of Zürich, Thema „TBA“
05.07.2018: Prof. Dr. Stephan A. Sieber, Technische Universität München, Thema „TBA“
Termine im WS 2018:
26.10.2017: Prof. Dr. Manfred Scheer, Universität Regensburg,
„Kohlenstoff und Phosphor – Eine „schräge“ Partnerschaft“
16.11.2017: Prof. Dr. Uhl Werner, Universität Münster,
„Aluminium-Phosphor-basierte Frustrierte Lewis-Paare – P-H-Funktionalisierung und Reaktionen mit a,b-ungesättigten Carbonyl-Verbindungen“
07.12.2017: Prof. Dr. Michael Hill, University of Bath, UK,
„Nucleophilic boron: the easy way“
21.12.2017: Prof. Dr. Oliver Wenger, University of Basel,
„From Photoinduced Electron Transfer to Charge Accumulation and New Photosensitizers“
18.01.2018: Prof. Dr. Angela Casini, Cardiff University,
„A golden future in bioinorganic chemistry: the promise of bioactive gold complexes as probes and therapeutic agents“
25.01.2018: Prof. Dr. Nicolas Winssinger, University of Geneva, Switzerland,
„PNA-programmed Self Assemblies in Chemical Biology“