Olsson, Christoffer; Swenson, Jan
The role of disaccharides for proteinprotein interactions a SANS study
The disaccharide trehalose has shown outstanding anti-aggregation properties for proteins, which are highly important for the possibility to treat neurodegenerative diseases, such as Alzheimers and Huntingtons disease. However, the role and mechanism of trehalose for such stabilising effects are still largely unknown, partly because a direct structural picture of how…
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…
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,…
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…
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,…
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…
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 ±…
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…
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…
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…