The aggregation of β-amyloid peptide (Aβ) is one potential cause for Alzheimer's disease (AD). Heparin can either promote or inhibit Aβ aggregation. The sulfation pattern and chain size determine its binding affinity and its role. Using 2D-NMR analysis and molecular modelling, the binding motif of heparin oligoaccharides to Aβ was determined to be HexA-GlcNS-IdoA2S-GlcNS6S. Iduronic acid epimerization and 6-O-sulfation are key factors for the binding affinity, while 3-O-sulfation of Arixtra (heparin pentasaccharide) is not involved in the binding to Aβ. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) was used to study the glycosaminoglycan (GAG)-peptide complex and identified V12HHQKL17 as the binding site of GAG at Aβ. Furthermore, an MTT assay was applied to evaluate the anti-Aβ fibril formation function of heparin tetrasaccharide, and indicated that the heparin tetrasaccharide with the defined sequence represents a promising inhibitor of Aβ aggregation.
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http://dx.doi.org/10.3389/fmolb.2022.824146 | DOI Listing |
J Biol Chem
December 2018
From the Department of Biology, Faculty of Science and Engineering and
ClpB, a bacterial homologue of heat shock protein 104 (Hsp104), can disentangle aggregated proteins with the help of the DnaK, a bacterial Hsp70, and its co-factors. As a member of the expanded superfamily of ATPases associated with diverse cellular activities (AAA), ClpB forms a hexameric ring structure, with each protomer containing two AAA modules, AAA1 and AAA2. A long coiled-coil middle domain (MD) is present in the C-terminal region of the AAA1 and surrounds the main body of the ring.
View Article and Find Full Text PDFBiosci Rep
December 2017
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, U.S.A.
Front Mol Biosci
February 2017
Center for Molecular Biology of the Heidelberg University, German Cancer Research Center Heidelberg, Germany.
The members of the hexameric AAA+ disaggregase of and , ClpB, and Hsp104, cooperate with the Hsp70 chaperone system in the solubilization of aggregated proteins. Aggregate solubilization relies on a substrate threading activity of ClpB/Hsp104 fueled by ATP hydrolysis in both ATPase rings (AAA-1, AAA-2). ClpB/Hsp104 ATPase activity is controlled by the M-domains, which associate to the AAA-1 ring to downregulate ATP hydrolysis.
View Article and Find Full Text PDFJ Biol Chem
April 2015
From the Department of Biology, Faculty of Science and Engineering and the Institute for Integrative Neurobiology, Konan University, Okamoto 8-9-1, Kobe 658-8501, Japan
FEBS J
July 2011
Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Japan.
ClpB, a member of the expanded superfamily of ATPases associated with diverse cellular activities (AAA+), forms a ring-shaped hexamer and cooperates with the DnaK chaperone system to reactivate aggregated proteins in an ATP-dependent manner. The ClpB protomer consists of an N-terminal domain, an AAA+ module (AAA-1), a middle domain, and a second AAA+ module (AAA-2). Each AAA+ module contains highly conserved WalkerA and WalkerB motifs, and two arginines (AAA-1) or one arginine (AAA-2).
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