Structural biology

ApplicationCharacterizationCustomer publicationsFoodFood scienceMaterialProteins & DNA/RNASAXSSelf-assembled materialShapeSizeStructural biologyTechnique

The influence of pH, protein concentration and calcium ratio on the formation and structure of nanotubes from partially hydrolyzed bovine ?-lactalbumin

Geng, XiaoLu; Kirkensgaard, Jacob Judas Kain; Arleth, Lise; Otte, Jeanette; Ipsen, Richard

Formation of nanotubes from partially hydrolysed ?-lactalbumin (?-La) was investigated at five pH values, two concentrations of ?-La and two calcium levels. Nanotubes were formed under almost all combinations of the investigated factors, and for the first time the formation of nanotubes at low pH (4.0) and low protein concentration…
27 January 2020
ApplicationCharacterizationCustomer publicationsLipidsMaterialPhase analysisSAXSShapeSizeStructural biologyTechnique

Effects of artepillin C on model membranes displaying liquid immiscibility

Pazin, W. M.; Vilanova, N.; Voets, I. K.; Soares, A. E. E.; Ito, A. S.

It has been hypothesized that the therapeutic effects of artepillin C, a natural compound derived from Brazilian green propolis, are likely related to its partition in the lipid bilayer component of biological membranes. To test this hypothesis, we investigated the effects of the major compound of green propolis, artepillin C,…
27 January 2020
ApplicationCharacterizationCustomer publicationsLipidsLiquid crystalsMaterialPhase analysisSAXSStructural biologyTechniqueTemperature

Cellular uptake of self-assembled phytantriol-based hexosomes is independent of major endocytic machineries

Rodrigues, Letícia; Schneider, Fabian; Zhang, Xiaohan; Larsson, Elin; Moodie, Lindon W. K.; Dietz, Hendrik; Papadakis, Christine M.; Winter, Gerhard; Lundmark, Richard; Hubert, Madlen

Despite increasing interests in non-lamellar liquid crystalline dispersions, such as hexosomes, for drug delivery, little is known about their interactions with cells and mechanism of cell entry. Here we examine the cellular uptake of hexosomes based on phytantriol and mannide monooleate by HeLa cells using live cell microscopy in comparison…
27 January 2020
ApplicationCharacterizationCustomer publicationsMaterialOtherParticle interactionsProteins & DNA/RNASAXSSelf-assembled materialShapeSizeStructural biologyTechnique

Twisted Ribbon Aggregates in a Model Peptide System

Rüter, Axel; Kuczera, Stefan; Pochan, Darrin J.; Olsson, Ulf

The model peptides A8K and A10K self-assemble in water into ca. 100 nm long ribbon-like aggregates. These structures can be described as ?-sheets laminated into a ribbon structure with a constant elliptical cross-section of 4 by 8 nm, where the longer axis corresponds to a finite number, N ? 15,…
27 January 2020
ApplicationCharacterizationCustomer publicationsFibersFractal dimensionMaterialPhase analysisProteins & DNA/RNASAXSSelf-assembled materialStructural biologyTechniqueWAXS

Aggregation behavior of the amyloid model peptide NACore

Pallbo, Jon; Sparr, Emma; Olsson, Ulf

The aggregation of the 11 residue long NACore peptide segment of ?-synuclein (68-GAVVTGVTAVA-78) has been investigated using a combination of cryogenic transmission electron microscopy (cryo-TEM), small- and wide-angle X-ray scattering, and spectroscopy techniques. The aqueous peptide solubility is pH dependent, and aggregation was triggered by a pH quench from pH…
27 January 2020
(Natural) polymersApplicationCharacterizationCustomer publicationsLipidsMaterialPhase analysisSAXSShapeSizeStructural biologyTechnique

Shape and Phase Transitions in a PEGylated Phospholipid System

Viitala, Lauri; Pajari, Saija; Gentile, Luigi; Määttä, Jukka; Gubitosi, Marta; Deska, Jan; Sammalkorpi, Maria; Olsson, Ulf; Murtomäki, Lasse

Poly(ethylene glycol) (PEG) polymers and PEG-conjugated lipids are widely used in bioengineering and drug transport applications. A PEG layer in a drug carrier increases hydrophilic repulsion, inhibits membrane fusion and serum opsonin interactions, and prolongs the storage and circulation time. It can also change the carrier shape and have an…
27 January 2020
ApplicationCharacteristic dimensionCharacterizationCustomer publicationsFibersMaterialProteins & DNA/RNAStructural biologyTechniqueWAXS

PrP (58–93) peptide from unstructured N-terminal domain of human prion protein forms amyloid-like fibrillar structures in the presence of Zn2+ ions

Gielnik, Maciej; Pietralik, Zuzanna; Zhukov, Igor; Szymańska, Aneta; Kwiatek, Wojciech M.; Kozak, Maciej

Many transition metal ions modulate the aggregation of different amyloid peptides. Substoichiometric zinc concentrations can inhibit aggregation, while an excess of zinc can accelerate the formation of cytotoxic fibrils. In this study, we report the fibrillization of the octarepeat domain to amyloid-like structures. Interestingly, this self-assembling process occurred only in…
25 November 2019
ApplicationCharacterizationCustomer publicationsMaterialProteins & DNA/RNASAXSShapeStructural biologyTechnique

NMR and crystallographic structural studies of the extremely stable monomeric variant of human cystatin C with single amino acid substitution

Maszota‐Zieleniak, Martyna; Jurczak, Przemyslaw; Orlikowska, Marta; Zhukov, Igor; Borek, Dominika; Otwinowski, Zbyszek; Skowron, Piotr; Pietralik, Zuzanna; Kozak, Maciej; Szymańska, Aneta; Rodziewicz‐Motowidło, Sylwia

Human cystatin C (hCC), a member of the superfamily of papain-like cysteine protease inhibitors, is the most widespread cystatin in human body fluids. This small protein, in addition to its physiological function, is involved in various diseases, including cerebral amyloid angiopathy, cerebral hemorrhage, stroke, and dementia. Physiologically active hCC is…
25 November 2019
ApplicationCharacterizationCustomer publicationsMaterialProteins & DNA/RNASAXSShapeStructural biologyTechnique

Arguments for an additional long-lived intermediate in the photocycle of the full-length aureochrome 1c receptor: A time-resolved small-angle X-ray scattering study

Bannister, Saskia; Böhm, Elena; Zinn, Thomas; Hellweg, Thomas; Kottke, Tilman

Aureochromes (AUREO) act as blue-light photoreceptors in algae. They consist of a light-, oxygen-, voltage-sensitive (LOV) domain and a DNA-binding basic region/leucine zipper. Illumination of the flavin cofactor in LOV leads to the formation of an adduct, followed by global structural changes. Here, we first applied UV/vis spectroscopy to characterize…
25 November 2019
ApplicationCharacterizationCustomer publicationsMaterialSAXSSelf-assembled materialShapeSizeStructural biologySurfactantsTechniqueTemperature

Self-Assembly of the Bio-Surfactant Aescin in Solution: A Small-Angle X-ray Scattering and Fluorescence Study

Dargel, Carina; Geisler, Ramsia; Hannappel, Yvonne; Kemker, Isabell; Sewald, Norbert; Hellweg, Thomas

This work investigates the temperature-dependent micelle formation as well as the micellar structure of the saponin aescin. The critical micelle concentration ( cmc ) of aescin is determined from the concentration-dependent autofluorescence (AF) of aescin. Values between cmcaescin,AF (10°C) = 0.38 ± 0.09 mM and cmcaescin,AF (50°C) = 0.32 ±…
25 November 2019