A5010576393- DNA and Nucleic Acid Chemistry
- RNA and protein synthesis mechanisms
- Bacteriophages and microbial interactions
- Force Microscopy Techniques and Applications
- Advanced biosensing and bioanalysis techniques
- Protein Structure and Dynamics
- RNA Interference and Gene Delivery
- Enzyme Structure and Function
- RNA Research and Splicing
- Nanopore and Nanochannel Transport Studies
- RNA modifications and cancer
- Microfluidic and Bio-sensing Technologies
- Mechanical and Optical Resonators
- Genomics and Chromatin Dynamics
- Molecular Biology Techniques and Applications
- Orbital Angular Momentum in Optics
- Molecular Junctions and Nanostructures
- SARS-CoV-2 and COVID-19 Research
- Electrostatics and Colloid Interactions
- Spectroscopy and Quantum Chemical Studies
- Surfactants and Colloidal Systems
- Advanced Fluorescence Microscopy Techniques
- Lipid Membrane Structure and Behavior
- Platelet Disorders and Treatments
- Monoclonal and Polyclonal Antibodies Research
Ludwig-Maximilians-Universität München
2016-2025
Center for NanoScience
2016-2025
Utrecht University
2022-2025
University of Augsburg
2024-2025
Nanomaterials Research (United States)
2023-2025
LMU Klinikum
2014-2022
Nanosystems Initiative Munich
2014-2020
Technische Universität Braunschweig
2019
Technical University of Munich
2019
Delft University of Technology
2008-2018
Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins functional structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC) currently relies on empirical screening detergents, stable PDC is often not obtained. To foundation systematic comparisons between properties detergent micelle resulting PDC, comprehensive set commonly used protein studies...
Small-angle X-ray scattering (SAXS) is increasingly used to characterize the structure and interactions of biological macromolecules their complexes in solution. Although still a low-resolution technique, advent high-flux synchrotron sources development algorithms for reconstruction 3-D electron density maps from 1-D profiles have made possible generation useful molecular models SAXS data. Furthermore, well suited study unfolded or partially folded conformational ensembles as function time...
The ion atmosphere around nucleic acids critically affects biological and physical processes such as chromosome packing, RNA folding, molecular recognition. However, the dynamic nature of renders it difficult to characterize. basic thermodynamic description this atmosphere, a full accounting type number associated ions, has remained elusive. Here we provide first complete using buffer equilibration atomic emission spectroscopy (BE-AES) accurately quantitate cation association anion...
We present a systematic analysis of the aggregation number and shape micelles formed by nine detergents commonly used in study membrane proteins. Small-angle X-ray scattering measurements are reported for glucosides with 8 9 alkyl carbons (OG/NG), maltosides phosphocholines 10 12 (DM/DDM FC-10/FC-12), 1,2-dihexanoyl-sn-glycero-phosphocholine (DHPC), 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] (LPPG), 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS). The...
Significance RNA, like DNA, can form double helices held together by the pairing of complementary bases, and such are ubiquitous in functional RNAs. Here we apply external forces torques to individual double-stranded RNA molecules determine mechanical properties conformational transitions these fundamental biological building blocks. For small torques, behave elastic rods, have determined their bending, stretching, twisting stiffness. Surprisingly, find that shortens when it is overwound,...
Short single-stranded nucleic acids are ubiquitous in biological processes; understanding their physical properties provides insights to acid folding and dynamics. We used small-angle x-ray scattering study 8--100 residue homopolymeric DNAs solution, without external forces or labeling probes. Poly-T's structural ensemble changes with increasing ionic strength a manner consistent polyelectrolyte persistence length theory that accounts for molecular flexibility. For any number of residues,...
The double-stranded nature of DNA links its replication, transcription and repair to rotational motion torsional strain. Magnetic tweezers (MT) are a powerful single-molecule technique apply both forces torques individual or RNA molecules. However, conventional MT do not track directly constrain the free rotation nucleic acid tether. Here we present freely orbiting (FOMT) that allow measurement equilibrium fluctuations changes in twist tethered Using precisely aligned vertically oriented...
Recent magnetic tweezers experiments have reported systematic deviations of the twist response double-stranded DNA from predictions twistable wormlike chain model. Here we show, by means analytical results and computer simulations, that these discrepancies can be resolved if a coupling between bend is introduced. We obtain an estimate 40±10 nm for twist-bend constant. Our simulations are in good agreement with high-resolution, magnetic-tweezers torque data. Although existence was predicted...
Significance The physiological function of proteins is often critically regulated by mechanical forces acting on them. Single-molecule manipulation techniques such as atomic force microscopy or optical tweezers have enabled unprecedented insights into the molecular mechanisms underlying regulation. Current limitations include resolution at low and throughput. We here introduce a versatile, modular approach for measurements in magnetic that allows probing dozens single molecules parallel,...
SYBR Gold is a commonly used and particularly bright fluorescent DNA stain, however, its chemical structure unknown binding mode to remains controversial. Here, we solve the of by NMR mass spectrometry be [2-[N-(3-dimethylaminopropyl)-N-propylamino]-4-[2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene]-1-phenyl-quinolinium] determine extinction coefficient. We quantitate using two complementary approaches. First, use single-molecule magnetic tweezers (MT) effects on length twist. The...
Significance In the dynamic environment of airways, where SARS-CoV-2 infections are initiated by binding to human host receptor ACE2, mechanical stability viral attachment is a crucial fitness advantage. Using single-molecule force spectroscopy techniques, we mimic effect coughing and sneezing, thereby testing RBD:ACE2 interaction under physiological conditions. Our results reveal higher ACE2 compared SARS-CoV-1, causing possible assay sensitive blocking agents preventing bond formation. It...
Abstract The structure and properties of DNA depend on the environment, in particular ion atmosphere. Here, we investigate how twist -one central DNA- changes with concentration identity surrounding ions. To resolve cations influence twist, combine single-molecule magnetic tweezer experiments extensive all-atom molecular dynamics simulations. Two interconnected trends are observed for monovalent alkali divalent alkaline earth cations. First, increases monotonously increasing all ions...
Polyproline type II (PPII) helix has emerged recently as the dominant paradigm for describing conformation of unfolded polypeptides. However, most experimental observables used to characterize proteins typically provide only short-range, sequence-local structural information that is both time- and ensemble-averaged, giving limited detail about long-range structure chain. Here, we report a study property: radius gyration an alanine-based peptide, Ace-(diaminobutyric acid) 2 -(Ala) 7...
DNA-binding small molecules are widespread in the cell and heavily used biological applications. Here, we use magnetic tweezers, which control force torque applied to single DNAs, study three molecules: ethidium bromide (EtBr), a well-known intercalator; netropsin, minor-groove binding anti-microbial drug; topotecan, clinically anti-tumor drug. In low-force limit biologically relevant torques can be accessed (<10 pN), show that intercalation lengthens DNA ∼1.5-fold decreases persistence...