FMP Publications

Our publications are recorded in a searchable database since 2010, updates will be added regularly.

Year:  
All :: 2010, ... , 2014, 2015, 2016, 2017
Author:  
All :: (, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z 
Preferences: 
References per page: Show keywords Show abstracts
References
Temperature dependence of cross-effect dynamic nuclear polarization in rotating solids: advantages of elevated temperatures
Geiger, M. A., Orwick-Rydmark, M., Marker, K., Franks, W. T., Akhmetzyanov(*), D., Stöppler, D., Zinke, M., Specker, E., Nazare, M., Diehl, A., van Rossum, B. J., Aussenac(*), F., Prisner(*), T., Akbey, Ü.; Oschkinat, H.
Phys Chem Chem Phys, 18:30696-30704
(2016)

Tags: NMR-Supported Structural Biology (Oschkinat), Medicinal Chemistry (Nazare), Molecular Biophysics (Lange, A.)

Abstract: Dynamic nuclear polarization exploits electron spin polarization to boost signal-to-noise in magic-angle-spinning (MAS) NMR, creating new opportunities in materials science, structural biology, and metabolomics studies. Since protein NMR spectra recorded under DNP conditions can show improved spectral resolution at 180-200 K compared to 110 K, we investigate the effects of AMUPol and various deuterated TOTAPOL isotopologues on sensitivity and spectral resolution at these temperatures, using proline and reproducibly prepared SH3 domain samples. The TOTAPOL deuteration pattern is optimized for protein DNP MAS NMR, and signal-to-noise per unit time measurements demonstrate the high value of TOTAPOL isotopologues for Protein DNP MAS NMR at 180-200 K. The combined effects of enhancement, depolarization, and proton longitudinal relaxation are surprisingly sample-specific. At 200 K, DNP on SH3 domain standard samples yields a 15-fold increase in signal-to-noise over a sample without radicals. 2D and 3D NCACX/NCOCX spectra were recorded at 200 K within 1 and 13 hours, respectively. Decreasing enhancements with increasing 2H-content at the CH2 sites of the TEMPO rings in CD3-TOTAPOL highlight the importance of protons in a sphere of 4-6 A around the nitroxyl group, presumably for polarization pickup from electron spins.

Design and comparison of exchange spectroscopy approaches to cryptophane-xenon host-guest kinetics
Korchak(*), S., Kilian(*), W., Schröder, L.; Mitschang(*), L.
J Magn Reson, 265:139-145
(2016)

Tags: Molecular Imaging (Schröder)

Abstract: Exchange spectroscopy is used in combination with a variation of xenon concentration to disentangle the kinetics of the reversible binding of xenon to cryptophane-A. The signal intensity of either free or crytophane-bound xenon decays in a manner characteristic of the underlying exchange reactions when the spins in the other pool are perturbed. Three experimental approaches, including the well-known Hyper-CEST method, are shown to effectively entail a simple linear dependence of the signal depletion rate, or of a related quantity, on free xenon concentration. This occurs when using spin pool saturation or inversion followed by free exchange. The identification and quantification of contributions to the binding kinetics is then straightforward: in the depletion rate plot, the intercept at the vanishing free xenon concentration represents the kinetic rate coefficient for xenon detachment from the host by dissociative processes while the slope is indicative of the kinetic rate coefficient for degenerate exchange reactions. Comparing quantified kinetic rates for hyperpolarized xenon in aqueous solution reveals the high accuracy of each approach but also shows differences in the precision of the numerical results and in the requirements for prior knowledge. Because of their broad range of applicability the proposed exchange spectroscopy experiments can be readily used to unravel the kinetics of complex formation of xenon with host molecules in the various situations appearing in practice.

Sulindac Sulfide Induces the Formation of Large Oligomeric Aggregates of the Alzheimer's Disease Amyloid-beta Peptide Which Exhibit Reduced Neurotoxicity
Prade(*), E., Barucker(*), C., Sarkar(*), R., Althoff-Ospelt(*), G., Lopez del Amo, J. M., Hossain(*), S., Zhong(*), Y., Multhaup(*), G.; Reif(*), B.
Biochemistry, 55:1839-1849
(2016)

Tags: Solid-State NMR Spectroscopy (Reif)

Abstract: Alzheimer's disease is characterized by deposition of the amyloid beta-peptide (Abeta) in brain tissue of affected individuals. In recent years, many potential lead structures have been suggested that can potentially be used for diagnosis and therapy. However, the mode of action of these compounds is so far not understood. Among these small molecules, the nonsteroidal anti-inflammatory drug (NSAID) sulindac sulfide received a lot of attention. In this manuscript, we characterize the interaction between the monomeric Abeta peptide and the NSAID sulindac sulfide. We find that sulindac sulfide efficiently depletes the pool of toxic oligomers by enhancing the rate of fibril formation. In vitro, sulindac sulfide forms colloidal particles which catalyze the formation of fibrils. Aggregation is immediate, presumably by perturbing the supersaturated Abeta solution. We find that sulindac sulfide induced Abeta aggregates are structurally homogeneous. The C-terminal part of the peptide adopts a beta-sheet structure, whereas the N-terminus is disordered. The salt bridge between D23 and K28 is present, similar as in wild type fibril structures. (13)C-(19)F transferred echo double resonance experiments suggest that sulindac sulfide colocalizes with the Abeta peptide in the aggregate.

Lysosomal Dysfunction Caused by Cellular Accumulation of Silica Nanoparticles
Schütz, I., Lopez-Hernandez, T., Gao(*), Q., Puchkov, D., Jabs, S., Nordmeyer(*), D., Schmudde(*), M., Rühl(*), E., Graf(*), C. M.; Haucke, V.
J Biol Chem, 291:14170-14184
(2016)

Tags: Molecular Pharmacology and Cell Biology (Haucke), Physiology and Pathology of Ion Transport (Jentsch), Cellular Imaging (Wiesner, Puchkov)

Abstract: Nanoparticles (NPs) are widely used as components of drugs or cosmetics and hold great promise for biomedicine, yet their effects on cell physiology remain poorly understood. Here we demonstrate that clathrin-independent dynamin 2-mediated caveolar uptake of surface-functionalized silica nanoparticles (SiNPs) impairs cell viability due to lysosomal dysfunction. We show that internalized SiNPs accumulate in lysosomes resulting in inhibition of autophagy-mediated protein turnover and impaired degradation of internalized epidermal growth factor, whereas endosomal recycling proceeds unperturbed. This phenotype is caused by perturbed delivery of cargo via autophagosomes and late endosomes to SiNP-filled cathepsin B/L-containing lysosomes rather than elevated lysosomal pH or altered mTOR activity. Given the importance of autophagy and lysosomal protein degradation for cellular proteostasis and clearance of aggregated proteins, these results raise the question of beneficial use of NPs in biomedicine and beyond.

5-Aryl-2-(naphtha-1-yl)sulfonamido-thiazol-4(5H)-ones as clathrin inhibitors
Robertson(*), M. J., Horatscheck, A., Sauer, S., von Kleist(*), L., Baker, J. R., Stahlschmidt, W., Nazare, M., Whiting(*), A., Chau(*), N., Robinson(*), P. J., Haucke, V.; McCluskey(*), A.
Org Biomol Chem, 14:11266-11278
(2016)

Tags: Molecular Pharmacology and Cell Biology (Haucke), Medicinal Chemistry (Nazare)

Abstract: The development of a (Z)-5-((6,8-dichloro-4-oxo-4H-chromen-3-yl)methylene)-2-thioxothiazolidin-4-one (2), rhodanine-based lead that led to the Pitstop(R) 2 family of clathrin inhibitors is described herein. Head group substitution and bioisosteric replacement of the rhodanine core with a 2-aminothiazol-4(5H)-one scaffold eliminated off target dynamin activity. A series of N-substituents gave first phenylglycine (20, IC50 approximately 20 muM) then phenyl (25, IC50 approximately 7.1 muM) and 1-napthyl sulfonamide (26, Pitstop(R) 2 compound, IC50 approximately 1.9 muM) analogues with good activity, validating this approach. A final library exploring the head group resulted in three analogues displaying either slight improvements or comparable activity (33, 38, and 29 with IC50 approximately 1.4, 1.6 and 1.8 muM respectively) and nine others with IC50 < 10 muM. These results were rationalized using in silico docking studies. Docking studies predicted enhanced Pitstop(R) 2 family binding, not a loss of binding, within the Pistop(R) groove of the reported clathrin mutant invalidating recent assumptions of poor selectivity for this family of clathrin inhibitors.

RIM-binding protein 2 regulates release probability by fine-tuning calcium channel localization at murine hippocampal synapses
Grauel(*), M. K., Maglione, M., Reddy-Alla(*), S., Willmes(*), C. G., Brockmann(*), M. M., Trimbuch(*), T., Rosenmund(*), T., Pangalos(*), M., Vardar(*), G., Stumpf(*), A., Walter, A. M., Rost(*), B. R., Eickholt(*), B. J., Haucke, V., Schmitz(*), D., Sigrist(*), S. J.; Rosenmund(*), C.
Proc Natl Acad Sci U S A, 113:11615-11620
(2016)

Tags: Molecular Pharmacology and Cell Biology (Haucke), Molecular and Theoretical Neuroscience (Walter)

Abstract: The tight spatial coupling of synaptic vesicles and voltage-gated Ca2+ channels (CaVs) ensures efficient action potential-triggered neurotransmitter release from presynaptic active zones (AZs). Rab-interacting molecule-binding proteins (RIM-BPs) interact with Ca2+ channels and via RIM with other components of the release machinery. Although human RIM-BPs have been implicated in autism spectrum disorders, little is known about the role of mammalian RIM-BPs in synaptic transmission. We investigated RIM-BP2-deficient murine hippocampal neurons in cultures and slices. Short-term facilitation is significantly enhanced in both model systems. Detailed analysis in culture revealed a reduction in initial release probability, which presumably underlies the increased short-term facilitation. Superresolution microscopy revealed an impairment in CaV2.1 clustering at AZs, which likely alters Ca2+ nanodomains at release sites and thereby affects release probability. Additional deletion of RIM-BP1 does not exacerbate the phenotype, indicating that RIM-BP2 is the dominating RIM-BP isoform at these synapses.

Novel organic dyes for multicolor localization-based super-resolution microscopy
Lehmann, M., Lichtner, G., Klenz, H.; Schmoranzer, J.
J Biophotonics, 9:161-170
(2016)

Tags: Molecular Pharmacology and Cell Biology (Haucke)

Abstract: Precise multicolor single molecule localization-based microscopy (SMLM) requires bright probes with compatible photo-chemical and spectral properties to resolve distinct molecular species at the nanoscale. The accuracy of multicolor SMLM is further challenged by color channel crosstalk and chromatic alignment errors. These constrains limit the applicability of known reversibly switchable organic dyes for optimized multicolor SMLM. Here, we tested 28 commercially available dyes for their suitability to super-resolve a known cellular nanostructure. We identified eight novel dyes in different spectral regimes that enable high quality dSTORM imaging. Among those, the spectrally close dyes CF647 and CF680 comprise an optimal dye pair for spectral demixing-based, registration free multicolor dSTORM with low crosstalk. Combining this dye pair with the separately excited CF568 we performed 3-color dSTORM to image the relative nanoscale distribution of components of the endocytic machinery and the cytoskeleton.

Liquid storage of boar semen: Current and future perspectives on the use of cationic antimicrobial peptides to replace antibiotics in semen extenders
Schulze(*), M., Dathe, M., Waberski(*), D.; Müller(*), K.
Theriogenology, 85:39-46
(2016)

Tags: Peptide-Lipid-Interaction/ Peptide Transport (Dathe)

Abstract: Antibiotics are of great importance in boar semen extenders to ensure long shelf life of spermatozoa and to reduce transmission of pathogens into the female tract. However, the use of antibiotics carries a risk of developing resistant bacterial strains in artificial insemination laboratories and their spread via artificial insemination. Development of multiresistant bacteria is a major concern if mixtures of antibiotics are used in semen extenders. Minimal contamination prevention techniques and surveillance of critical hygiene control points proved to be efficient in reducing bacterial load and preventing development of antibiotic resistance. Nevertheless, novel antimicrobial concepts are necessary for efficient bacterial control in extended boar semen with a minimum risk of evoking antibiotic resistance. Enhanced efforts have been made in recent years in the design and use of antimicrobial peptides (AMPs) as alternatives to conventional antibiotics. The male genital tract harbors a series of endogenic substances with antimicrobial activity and additional functions relevant to the fertilization process. However, exogenic AMPs often exert dose- and time-dependent toxic effects on mammalian spermatozoa. Therefore, it is important that potential newly designed AMPs have only minor impacts on eukaryotic cells. Recently, synthetic magainin derivatives and cyclic hexapeptides were tested for their application in boar semen preservation. Bacterial selectivity, proteolytic stability, thermodynamic resistance, and potential synergistic interaction with conventional antibiotics propel predominantly cyclic hexapeptides into highly promising, leading candidates for further development in semen preservation. The time scale for the development of resistant pathogens cannot be predicted at this moment.

Current Status: Site-Specific Antibody Drug Conjugates
Schumacher, D., Hackenberger, C. P., Leonhardt(*), H.; Helma(*), J.
Journal of clinical immunology, 36 Suppl 1:100-107
(2016)

Tags: Chemical Biology II (Hackenberger)

Abstract: Antibody drug conjugates (ADCs), a promising class of cancer biopharmaceuticals, combine the specificity of therapeutic antibodies with the pharmacological potency of chemical, cytotoxic drugs. Ever since the first ADCs on the market, a plethora of novel ADC technologies has emerged, covering as diverse aspects as antibody engineering, chemical linker optimization and novel conjugation strategies, together aiming at constantly widening the therapeutic window for ADCs. This review primarily focuses on novel chemical and biotechnological strategies for the site-directed attachment of drugs that are currently validated for 2nd generation ADCs to promote conjugate homogeneity and overall stability.

Lipopeptide-based micellar and liposomal carriers: Influence of surface charge and particle size on cellular uptake into blood brain barrier cells
Sydow, K., Nikolenko, H., Lorenz, D., Müller(*), R. H.; Dathe, M.
Eur J Pharm Biopharm, 109:130-139
(2016)

Tags: Peptide-Lipid-Interaction/ Peptide Transport (Dathe)

Abstract: Lipopeptide-based micelles and liposomes were found to differ in cell recognition and uptake mode into blood brain barrier (BBB) endothelial cells. Here we analyse the role of size and surface charge of micelles and liposomes composed of different lipopeptide sequences with respect to uptake into human brain capillary (HBMEC) and aortic (HAoEC) endothelial cells. Comparable to the dipalmitoylated apolipoprotein E-derived P2A2, lipopeptides of cationic poly-arginine (P2Rn), poly-lysine (P2Kn) and an anionic glutamic-acid sequence (P2En) self assemble into micelles (12-14nm in diameter) with high surface charge density, and bind to small (SUVs, about 24nm in diameter) and large (LUV, about 100nm in diameter) liposomes at variable lipid to peptide ratios. The interaction pattern of the resulting particles with endothelial cells is highly variable as revealed by confocal laser scanning microscopic (CLSM) and fluorescence assisted cell sorting (FACS) studies. Micelles and SUVs with high P2A2 density are efficiently and selectively internalized into HBMEC. P2Kn micelles strongly accumulate in both the cytosol and at the cell membrane, while the interaction of liposomes tagged with a low amount of P2A2 and P2Kn with the cells was reduced. Anionic micelles seem to dissociate in the presence of cells and P2En molecules incorporate into the cellular membrane whereas the negatively charged liposomes hardly interact with cells. Surprisingly, all poly-R-based particles show high selectivity for HBMEC compared to HAoEC, independent of particle size and peptide surface density. The P2Rn-mediated internalization is highly efficient and partially clathrin-dependent. The oligo-R lipopeptide is considered to be most promising to selectively transport different drug carriers into the blood brain barrier.

Page:  
Previous | 1, 2, 3, 4, 5, 6, 7 | Next
Export as:
BibTeX, XML

Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP)
Campus Berlin-Buch
Robert-Roessle-Str. 10
13125 Berlin, Germany
+4930 94793 - 100 
+4930 94793 - 109 (Fax)
info(at)fmp-berlin.de

Like many sites, we use cookies to optimize the user's browsing experience. Data Protection OK