A5086605859- Antimicrobial Peptides and Activities
- Lipid Membrane Structure and Behavior
- Supramolecular Self-Assembly in Materials
- Chemical Synthesis and Analysis
- Analytical Chemistry and Sensors
- Biochemical and Structural Characterization
- RNA Interference and Gene Delivery
- Polydiacetylene-based materials and applications
- Bacteriophages and microbial interactions
- Water Quality Monitoring and Analysis
- RNA and protein synthesis mechanisms
- Analytical Chemistry and Chromatography
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced Chemical Sensor Technologies
- Glycosylation and Glycoproteins Research
- Spectroscopy and Chemometric Analyses
- Porphyrin and Phthalocyanine Chemistry
- Protein Structure and Dynamics
- RNA Research and Splicing
- Bacterial Genetics and Biotechnology
- Advanced Fiber Optic Sensors
- Nanocluster Synthesis and Applications
- Enzyme Structure and Function
- Crystallization and Solubility Studies
- Probiotics and Fermented Foods
Karlsruhe Institute of Technology
2015-2024
Interface (United States)
2017
Karlsruhe University of Education
2015-2017
Laboratoire de Physique des Interfaces et des Couches Minces
2011
National Institute for Materials Science
2010
National Institute of Advanced Industrial Science and Technology
2010
FZI Research Center for Information Technology
1991-2009
Lawrence Livermore National Laboratory
1994
Lawrence Berkeley National Laboratory
1994
There is some overlap in the biological activities of cell-penetrating peptides (CPPs) and antimicrobial (AMPs). We compared nine AMPs, seven CPPs, a fusion peptide with regard to their ability cluster anionic lipids mixture mimicking cytoplasmic membrane Gram-negative bacteria, as measured by differential scanning calorimetry. also studied bacteriostatic effect on several bacterial strains, examined conformational changes upon binding using circular dichroism. A remarkable correlation was...
Hydrophobic mismatch is important for pore-forming amphipathic antimicrobial peptides, as demonstrated recently [Grau-Campistany, A., et al. (2015) Sci. Rep. 5, 9388]. A series of different length peptides have been generated with the heptameric repeat sequence KIAGKIA, called KIA and it was found that only those helices sufficiently long to span hydrophobic thickness membrane could induce leakage in lipid vesicles; there also a clear dependence hemolytic activities. For original sequences,...
ConspectusThe structures of membrane-bound polypeptides are intimately related to their functions and may change dramatically with the lipid environment. Circular dichroism (CD) is a rapid analytical method that requires relatively low amounts material no labeling. Conventional CD routinely used monitor secondary structure peptides proteins in solution, for example, presence ligands other binding partners. In case membrane-active transmembrane proteins, these measurements can be applied to,...
PGLa and magainin 2 (MAG2) are amphiphilic α-helical membranolytic peptides from frog skin with known synergistic antimicrobial activity. By systematically mutating residues in the two it was possible to identify ones crucial for synergy, as monitored by biological assays, fluorescence vesicle leakage, solid-state 15N-NMR. Electrostatic interactions between anionic groups MAG2 cationic enhance synergy but not necessary effect. Instead, Gly (7 11) a so-called GxxxG motif synergy. Replacing...
Electrospinning is a promising method to mimic the native structure of extracellular matrix. Collagen material choice, since it natural fibrous structural protein. It an open question how much spinning process preserves or alters collagen. There are conflicting results in literature, mainly due different solvent systems use and fact that gelatin employed as reference state for completely unfolded collagen calculations. Here we used circular dichroism (CD) Fourier-transform infrared...
Dermcidin encodes the anionic amphiphilic peptide DCD-1L, which displays a broad spectrum of antimicrobial activity under conditions resembling those in human sweat. Here, we have investigated its mode activity. We found that DCD-1L interacts preferentially with negatively charged bacterial phospholipids helix axis is aligned flat on lipid bilayer surface. Upon interaction bilayers forms oligomeric complexes are stabilized by Zn2+. able to form ion channels membrane, and propose Zn2+-induced...
Abstract Compact myelin comprises most of the dry weight myelin, and its insulative nature is basis for saltatory conduction nerve impulses. The major dense line (MDL) a 3-nm compartment between two cytoplasmic leaflets stacked membranes, mostly occupied by basic protein (MBP) phase. MBP an abundant involved in demyelinating diseases, such as multiple sclerosis. association with lipid membranes has been studied decades, but MBP-driven formation MDL remains elusive at biomolecular level. We...
The cationic peptide [KIGAKI]3 was designed as an amphiphilic β-strand and serves a model for β-sheet aggregation in membranes. Here, we have characterized its molecular conformation, membrane alignment, dynamic behavior using solid-state 19F NMR. A detailed structure analysis of selectively 19F-labeled peptides carried out oriented DMPC bilayers. It showed concentration-dependent transition from monomeric β-strands to oligomeric β-sheets. In both states, the rigid side chains project...
Peptide-coated nanoparticles are valuable tools for diverse biological applications, such as drug delivery, molecular recognition, and antimicrobial action. The functionalization of pre-fabricated with free peptides in solution is inefficient either due to aggregation the particles or poor ligand exchange reaction. Here, we present a one-pot synthesis preparing gold homogeneous distribution that covered situ cationic site-selective manner via Cys-residue at N-terminus. Five representative...
Abstract Hydrophobic mismatch is a well-recognized principle in the interaction of transmembrane proteins with lipid bilayers. This concept was extended here to amphipathic membranolytic α-helices. Nine peptides lengths between 14 and 28 amino acids were designed from repeated KIAGKIA motifs their helical nature confirmed by circular dichroism spectroscopy. Biological assays for antimicrobial activity hemolysis, as well fluorescence vesicle leakage solid-state NMR spectroscopy, used...
Abstract Compact myelin forms the basis of nerve insulation essential for higher vertebrates. Dozens membrane bilayers undergo tight stacking, and in peripheral nervous system, this is partially enabled by protein zero (P0). Consisting an immunoglobulin (Ig)-like extracellular domain, a single transmembrane helix, cytoplasmic extension (P0ct), P0 harbours important task ensuring integrity compact compartment, referred to as intraperiod line. Several disease mutations resulting neuropathies...
The ability to dynamically control chirality remains a grand challenge in chemistry. Although many molecules possess chiral isomers, lacking their isolation, for instance during photoisomerization, results racemic mixtures with suppressed enantiospecific properties. Here, we present nanoporous solid which and enantioselective enrichment is induced by circularly polarized light (CPL). material based on photoswitchable fluorinated azobenzenes attached the scaffold of crystalline metal-organic...
ABSTRACT The mode of action short, nonhelical antimicrobial peptides is still not well understood. Here we show that these interact with ATP and directly inhibit the actions certain ATP-dependent enzymes, such as firefly luciferase, DnaK, DNA polymerase. α-Helical planar or circular did interaction ATP.
According to their distinct biological functions, membrane-active peptides are generally classified as antimicrobial (AMP), cell-penetrating (CPP), or fusion (FP). The former two classes known have some structural and physicochemical similarities, but fusogenic tend rather different features sequences. Nevertheless, we found that many CPPs AMPs exhibit a pronounced activity, measured by lipid mixing assay with vesicles composed of typical eukaryotic lipids. Compared the HIV peptide (FP23)...
Background: Dimerization regulates activation of PDGF receptor in signal transduction.Results: The transmembrane segment PDGFR forms a left-handed helical dimer, which becomes more tilted and less stable model membranes with decreasing lipid acyl chain lengths.Conclusion: membrane thickness controls the ability segments to dimerize.Significance: Receptor dimerization vivo may require relocation thick rafts. transduction. Results: lengths. Conclusion: dimerize. Significance:
Abstract Oriented circular dichroism (OCD) is explored and successfully applied to investigate chiral surface‐anchored metal–organic frameworks (SURMOFs) based on camphoric acid (D‐ Lcam) with the composition [Cu 2 (Dcam) x (Lcam) 2−2 (dabco)] n (dabco=1,4‐diazabicyclo‐[2.2.2]‐octane). The three‐dimensional SURMOFs high‐quality orientation were grown quartz glass plates by using a layer‐by‐layer liquid‐phase epitaxy method. growth orientation, as determined X‐ray diffraction (XRD), could be...
SB056 is a novel semi-synthetic antimicrobial peptide with dimeric dendrimer scaffold. Active against both Gram-negative and -positive bacteria, its mechanism has been attributed to disruption of bacterial membranes. The branched was shown assume β-stranded conformation in lipidic environment. Here, we report on rational modification the original, empirically derived linear sequence [WKKIRVRLSA-NH2, SB056-lin]. We interchanged first two residues [KWKIRVRLSA-NH2, β-SB056-lin] enhance...
The first example of a planar-chiral building block being used for chiral metal–organic frameworks (MOFs) is presented.
A chiral photoswitchable nanoporous material with remote-controllable enantioselective adsorption capacity is presented. This metal-organic framework possesses both homochiral d-camphoric acid and light-responsive azobenzene moieties. Although the structure at moieties unaffected, trans-cis-azobenzene-photoisomerization changes pore environment and, thus, switches behavior of MOF.
Integrative structure of a complete cytokine receptor in nanodisc opens for mechanistic decoding disorder-based biology.
Abstract Electronic circular dichroism is an important optical phenomenon offering insights into chiral molecular materials. On the other hand, metal–organic frameworks (MOFs) are a novel group of crystalline porous thin‐film materials that provide tailor‐made chemical and physical properties by carefully selecting their building units. Combining these two aspects contemporary material research integrating molecules MOFs promises devices with unprecedented functionality. However, considering...
A fiber-optic evanescent field absorbance sensor (EFAS) is described, for which the sensing element consists of a commercially available silicone-clad quartz glass fiber, coiled on Teflon® support. The polydimethylsiloxane cladding fulfills various functions. It protects brittle fiber core against fracture induced by mechanical stress. Moreover, as lower-refractive-index medium, it causes total reflection in and acts hydrophobic membrane that enriches nonpolar organic compounds, whereas...