Beta-amyloid (1-40) (Abeta), the main component of senile plaques seen in the brains of Alzheimer's disease patients, was found to be toxic both as fibrils and smaller soluble globular aggregates. The hydrolytic properties of Abeta, a new biochemical activity described previously [Brzyska M, Bacia A & Elbaum D (2001) Eur J Biochem 268, 3443-3454], may contribute to its overall toxicity. In this study, the hydrolysis of fluorescein ester series was studied under predetermined conditions affecting Abeta hydrophobicity and conformation. Reaction products of the most effectively decomposed ester (dibutyrate) were characterized using HPLC and ESI-MS. Hydrophobicity of Abeta, as measured by bis-8-anilinonaphthalene fluorescence, correlated with its hydrolytic abilities. FTIR and CD data analysis showed a relationship between enhanced hydrolytic abilities and Abeta structure. Seriously limited hydrolysis caused by higher peptide concentrations is consistent with monomeric/dimeric Abeta species participation in the process, confirmed by thioflavine T binding. Inhibition of hydrolysis was caused by beta-sheet breaker peptide (LPFFD), indicating that the Abeta central hydrophobic cluster (amino acids 17-21) participates in the process. The reported Abeta properties suggest that small conformational alterations of the peptide structure may have a pronounced effect on its functions and biological activity.
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http://dx.doi.org/10.1111/j.1742-4658.2006.05549.x | DOI Listing |
Polymers (Basel)
January 2025
Faculty of Mechanical Engineering, Bialystok University of Technology, Wiejska 45C, 15-351 Bialystok, Poland.
This article presents the characteristics of composites comprising polylactide combined with iron powder, from 1 to 10 wt.%, and nanoiron powders with a mass fraction from 0.1 to 1.
View Article and Find Full Text PDFMicroorganisms
January 2025
Department of Food Science and Technologies for Sustainable Agro-Food Chain (DiSTAS), Università Cattolica del Sacro Cuore, 29122 Piacenza, PC, Italy.
This study investigated whether viable cells, dead cells or cell-free supernatants (CFS) were responsible for the biocontrol effect of strains from two important bacterial genera, and , known for their antifungal properties against plant pathogens and food spoilage microorganisms. Specifically, the capability of these strains to produce extracellular hydrolytic enzymes on specified media was assessed, along with their effectiveness in inhibiting the mycelial growth of several phytopathogenic fungi (, , and ) using dual culture plate assays. Results from these inhibition assays revealed that PF05 and LMG 23520 strains were the most effective in suppressing fungal growth, especially .
View Article and Find Full Text PDFJ Org Chem
January 2025
Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
Spin labels based on Gd complexes are important tools for the elucidation of the structure, dynamics and interaction of biomolecules by electron paramagnetic resonance (EPR) spectroscopy. Their EPR spectroscopic properties line width and relaxation times influence their performance in a particular application. To be able to apply a complex well-suited for a specific application, a set of Gd complexes with different EPR spectroscopic properties ready-made for spin labeling will be highly useful.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, China.
We successfully synthesize monodisperse sulfhydryl-modified mesoporous organosilica nanospheres (MONs-SH) via one-step hydrolytic condensation, where cetyltrimethylammonium chloride and dodecyl sulfobetaine are employed as dual-template agents with (3-mercaptopropyl)triethoxysilane and 1,2-bis(triethoxysilyl)ethane as the precursors and concentrated ammonia as the alkaline catalyst. The prepared MONs-SHs deliver a large specific surface area (729.15 m g), excellent monodispersity, and homogeneous particle size.
View Article and Find Full Text PDFGels
December 2024
Department of Inorganic Chemistry, Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, 4-12 Regina Elisabeta Blvd., 030016 Bucharest, Romania.
Hydrogels are a viable option for biomedical applications due to their biocompatibility, biodegradability, and ability to incorporate various healing agents while maintaining their biological efficacy. This study focused on the preparation and characterization of novel hybrid hydrogels enriched with the natural algae compound Ulvan for potential use in wound dressings. The characterization of the hydrogel membranes involved multiple methods to assess their structural, mechanical, and chemical properties, such as pH measurements, swelling, moisture content and uptake, gel fraction, hydrolytic degradation, protein adsorption and denaturation tests, rheological measurements, SEM, biocompatibility testing, and scratch wound assay.
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