Little is known about the precise mechanism of action of beta-sheet ligands, hampered by the notorious solubility problems involved with protein misfolding and amyloid formation. Recently the nucleation site for the pathogenic aggregation of the Alzheimer's peptide was identified as the KLVFF sequence in the central region of Abeta. A combination of two aminopyrazole ligands with di- or tripeptides taken from this key fragment now furnished water-soluble Abeta-specific ligands which allow model investigations in water. A detailed conformational analysis provides experimental evidence for an increased beta-sheet content induced in the peptide. Strong indications were also found for the peptide backbone recognition via hydrogen bonds plus hydrophobic contributions between aminopyrazole nuclei and Phe residues. The affinity of these new ligands toward the KKLVFF fragment is highly dependent on their sequence and composition from natural and artificial amino acids. Thus, for the first time, detailed insight is gained into the complexation of beta-sheet ligands with model peptides taken directly from Abeta.
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http://dx.doi.org/10.1021/ja045558b | DOI Listing |
Chem Commun (Camb)
January 2025
Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pune-411008, India.
A superhelix is a three-dimensional arrangement of a helix in which the helix is coiled around a common axis. Here, we are reporting a short 12-helix of α,γ-hybrid peptides terminated by metal binding ligands, self-assembled into a right-handed superhelix around a common axis in the presence of Cd(II) ions. Furthermore, these superhelices are assembled into hierarchical superhelical β-sheet-type structural motifs in single crystals.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Pharmacology, Yale University School of Medicine, New Haven, CT, 06520, USA.
Sevenless, the Drosophila homologue of ROS1 (University of Rochester Sarcoma) (herein, dROS1) is a receptor tyrosine kinase (RTK) essential for the differentiation of Drosophila R7 photoreceptor cells. Activation of dROS1 is mediated by binding to the extracellular region (ECR) of the GPCR (G protein coupled receptor) BOSS (Bride Of Sevenless) on adjacent cells. Activation of dROS1 by BOSS leads to subsequent downstream signaling pathways including SOS (Son of Sevenless).
View Article and Find Full Text PDFNanoscale Adv
December 2024
The Department of Chemistry & Biochemistry, The University of Texas at El Paso 500 W. University Ave. El Paso TX 79968 USA
Carbon nanomaterials (CNMs), such as carbon nanotubes (CNTs), graphene quantum dots (GQDs), and carbon quantum dots (CQDs), are prevalent in biological systems and have been widely utilized in applications like environmental sensing and biomedical fields. While their presence in human matrices is projected to increase, the interfacial interactions between carbon-based nanoscopic platforms and biomolecular systems continue to remain underexplored. In this study, we investigated the effect of gelatin-sourced CQDs on the globular milk protein beta-lactoglobulin (BLG).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; Department of Pharmacy, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China. Electronic address:
J Biol Chem
December 2024
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, D-66123 Saarbrücken, Germany; Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig; Department of Chemistry, PharmaScienceHub (PSH), Saarland University, D-66123 Saarbrücken, Germany.
Bacteria frequently employ carbohydrate-binding proteins, so-called lectins, to colonize and persist in a host. Thus, bacterial lectins are attractive targets for the development of new antiinfectives. To find new potential targets for antiinfectives against pathogenic bacteria, we searched for homologs of Pseudomonas aeruginosa lectins and identified homologs of LecA in Enterobacter species.
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