Parkin – eine neuroprotektive E3-Ubiquitin-Ligase(S. 724)
Cathrin Schnack, Lena Berlemann, Konstanze F. Winklhofer
Mitochondrial dysfunction causes cellular damage and is linked to numerous pathological conditions. The prominent role of mitochondria in energy supply and cellular homeostasis highlights the importance of mitochon - drial quality control mechanisms to preserve organelle function under stress and to eliminate irreversibly damaged mitochondria. Recent research revealed that two genes associated with familial Parkinson’s disease, Parkin and PINK1, function in mitochondrial quality control pathways.
Wie Sekundärtransporter ihre interne Symmetrie zum Transport nutzen(S. 730)
Secondary transporters exploit the electrochemical gradient from one substrate to pump another substrate actively against its concentration gradient. This elegant mechanism of substrate coupling is based on a highly symmetric repeat architecture, which is shared by nearly all members of this structurally diverse family of membrane transport proteins pointing towards a common ancestor.
Zelluläre Stressantwort reguliert Proteinhomöostase und Alterung(S. 735)
Alexander Springehorn, Thorsten Hoppe
The maintenance of protein homeostasis (proteostasis) is key in preserving the healthy state of single cells and life expectancy of entire organisms. To ensure proteome integrity, stress responsive pathways are induced to counteract aggregate formation by boosting the cellular protein folding capacity. In addition, irreversibly damaged proteins are degraded in a ubiquitin-dependent manner by the proteasome or through autophagy. Here, we discuss the existing safeguard mechanisms in the context of aging and disease.
Wie Anaerobier Ferredoxin reduzieren(S. 738)
In clostridia the exergonic reduction of crotonyl-CoA to butyryl-CoA by NADH is coupled to the endergonic reduction of ferredoxin by NADH – a process called flavin-based electron bifurcation (FBEB). Similar systems are wide-spread in anaerobic bacteria and archaea, which use the reduced ferredoxin for CO2 reduction by H2 in aceto- and methanogenesis, for H2 formation in fermentations, and for generation of ΔμH+/Na+/ via a membrane bound ferredoxin-NAD reductase (Rnf).
Biosynthese und molekulare Wirkung von zyklischen Pflanzenpeptiden(S. 741)
Johannes Koehbach, Christian W. Gruber
Cyclotides are bioactive plant peptides that share the structural features of a head-to-tail cyclic backbone and three disulfide bonds in a knotted arrangement. This unique topology confers them exceptional stability. Cyclotides are expressed as precursor proteins and their biosynthesis involves multiple post-translational processing steps. Recently a specific molecular receptor of cyclotides has been identified emphasizing their potential for pharmaceutical and agrochemical applications.
Antibakterielle Strategien und bakterielle Abwehrmechanismen(S. 744)
Julia Bandow, Sina Langklotz
In the face of multi-resistant pathogens it is time to find new antibacterial strategies. A system-based approach to studying antibiotic action of natural compounds, antimicrobial peptides, and small molecules allows investigation of clinically unexploited antibiotic classes and targets as well as intrinsic bacterial defence mechanisms. We also investigate the antibacterial activity and mechanisms of action of technical plasmas (ionized gases). They are promising wound disinfectants, which are in clinical development to complement established antibiotic approaches.
FoxO und die Alterung sterblicher und unsterblicher Organismen(S. 747)
Thomas C. G. Bosch, Friederike Flachsbart
Understanding aging and how it affects an organism’s life span is a fundamental problem in biology. A journey into the evolutionary past of multicellular organisms facilitates the view of the function of FoxO during aging. Medicine and evolutionary developmental biology recognize the significance of FoxO. But basic research faces also new questions.
Gyrasen – biologische Werkzeuge zur Isolation bakterieller Nukleinsäuren(S. 751)
Natalia Sandetskaya, Katharina hennig, Andreas Naumann, Dirk Kuhlmeier
Targeted enrichment of DNA is often necessary for its detection in complex samples. We describe the development of a novel molecular tool for the specific enrichment of prokaryotic DNA. A fused protein comprising the DNA-binding subunit of the bacterial topoisomerase II, gyrase, was expressed and immobilized on magnetic particles. The specific affinity of the protein towards bacterial DNA in samples with high background of eukaryotic DNA was investigated.
Erkennung, Bindung, Signalgebung: Funktionsmoleküle für Biosensoren(S. 754)
Sebastian Kersting, Sebastian Hoppe, Frank F. Bier
Diagnostics are essential for detecting infectious agents and the assessment of a disease. In the joint research project “The Lab in a Hankie – Impulse Centre for Integrated Bioanalysis” the complete integration of all necessary processing steps was intended. Work has been done on a new class of sensor-actor molecules integrating detection and signalling and being applicable to complex matrices. Defining binding parts, assembly on a polymer scaffold, enabling signal generation and amplification were central goals of this project.
Molekulare Diagnostik bei soliden Tumoren(S. 758)
Frank Bartel, Udo Siebolts, Barbara Seliger, Claudia Wickenhauser
Recent advances in the analysis of processes in cancer cells at the mole - cular level have led to the development of new therapeutic strategies in the treatment of cancer. In addition, biomarkers have been discovered that predict the response to targeted therapies. Therefore, genetic testing is mandatory for cancer patients in order to identify individuals who will potentially benefit from treatment. The new therapeutic opportunities for cancer patients, the underlying pathways as well as the challenges for the pathologists will be discussed.
Anwendungen & Produkte
Objektive Zellkultur-Qualitätskontrolle durch infrarotspektroskopische Untersuchungen(S. 770)
Miriam Unger, Helmut Köster, Alice Popescu, Inka Pfitzner
Cell culture has become one of the major tools in life science today. In addition to the study of cell functions for fundamental research, the use of cell lines for the production of pharmaceutical substances is of great importance. Evaluating the general health of a cell culture is usually based on different cell characteristics. Mid-infrared spectroscopy in combination with chemometric methods proves to be highly suited for this purpose in terms of reproducibility, objectivity, cost- effectiveness and speed.
2D-Visualisierung des zellulären Sauerstoffverbrauchs in Mikrofluidiksystemen(S. 773)
Christopher J. Ochs, Junichi Kasuya, Andrea Pavesi, Gregor Liebsch
A new imaging system allows visualizing oxygen distributions in 2D. Combining sensor foils with microfluidic devices enables online monitoring of cellular oxygen consumption in whole chip areas. Furthermore, suitable device materials depending on application and cell line can be determined. Numerically simulated oxygen consumption of rat lung microvascular endothelial cells and rat hepatocytes was experimentally validated.
In vitro-Zytotoxizitätsanalyse mit humanen Primärhepatozyten(S. 776)
Brad Larson, Tim Moeller, Grant Cameron
Typically in vitro screening has incorporated primary hepatocytes cultured in a two dimensional (2D) format. However, when cultured and studied in this fashion they rapidly lose their key functions and dedifferentiate over the course of only a few days. Here we present data demonstrating the differences in response between human primary cells cultured in 2D and a new 3D cell culture system which has the benefits of a collagen hydrogel with tissue-like properties.
Gezielte Anreicherung bakterieller DNA(S. 780)
Dirk Osterloh, Susann Motzke, Martina Pick
Cytosine methylation and frequency of non-methylated CpG dinucleotides are genomic properties varying greatly between mammals and bacteria. A new DNA enrichment technology uses the specific affinity of the CXXC zinc finger domain for non-methylated CpG dinucleotides for powerful bacterial nucleic acid separation and enrichment. Application of the technology in sample preparation allows a 50-fold enrichment of minute amounts of bacterial DNA relative to a high mammalian DNA background.
Biomethanisierung – ein Prozess zur Ermöglichung der Energiewende?(S. 816)
Simon Rittmann, Arne H. Seifert, Alexander Krajete
Biomethanation is a biotechnological process for the production of methane from hydrogen and carbon dioxide, utilizing an archaeal group of microorganisms referred to as methanogens. Biomethanation can be performed by using pure and industrial emission waste gases in a continuous but also in discontinuous bioprocess mode. Volumetric methane productivity as high as 950 millimoles CH4 per litre and hour was achieved. Optimization of methane production regarding quality and quantity of methane is currently being examined.
Karriere, Köpfe & Konzepte
Sounds of Science – Wissenschaft im Musikclub(S. 825)
Vortragsreihe Science Notes