Three new hexa-Ni-substituted Keggin-type polyoxometalates (POMs), [Ni(OH)- (DACH)(HO)(PWO)]·31HO (), [Ni(DACH)][Ni(OH)(DACH)(HMIP)(HO)(PWO)]·56 HO (), and [Ni(DACH)][Ni(OH)(DACH)(AP)(HO)(PWO)]·2HO () (DACH = 1,2-Diami- nocyclohexane, MIP = 5-Methylisophthalate, AP = Adipate) were successfully made in the presence of DACH under hydrothermal conditions. is an isolated hexa-Ni-substituted Keggin unit decorated by DACH. In order to further construct POM cluster-organic frameworks (POMCOFs) on the basis of , by analyzing the steric hindrances and orientations of the POM units, the rigid HMIP and flexible AP ligands were successively incorporated, and another anionic monomeric POM and the new 1D POM cluster organic chain (POMCOC) were obtained. HMIP ligand still acts as a decorating group on the Ni core of but results in the different spatial arrangement of the {NiPW} units. AP ligands in successfully bridge adjacent isolated POM cluster units to 1D POMCOC with left-hand helices. The AP in is the longest aliphatic carboxylic acid ligand in POMs, and the 1D POM cluster-AP helical chain represents the first 1D POMCOC with a helical feature.
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http://dx.doi.org/10.3390/molecules27134295 | DOI Listing |
Gels
December 2024
Horváth Csaba Memorial Laboratory of Bioseparation Sciences, Research Center for Molecular Medicine, Faculty of Medicine, Doctoral School of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
Hydrogels like agarose have long been used as sieving media for the electrophoresis-based analysis of biopolymers. During gelation, the individual agarose strands tend to form hydrogen-bond mediated double-helical structures, allowing thermal reversibility and adjustable pore sizes for molecular sieving applications. The addition of tetrahydroxyborate to the agarose matrix results in transitional chemical cross-linking, offering an additional pore size adjusting option.
View Article and Find Full Text PDFProtein Sci
January 2025
Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain.
Peptides are attracting a growing interest for therapeutic applications in biomedicine. In Parkinson's disease (PD), different human endogenous peptides have been associated with beneficial effects, including protein aggregation inhibition, reduced inflammation, or the protection of dopaminergic neurons. Such effects seem to be connected to the spatial arrangement of peptide side chains, and many of these human molecules share common conformational traits, displaying a distinctive amphipathic and cationic helical structure, which is believed to be crucial for their activities.
View Article and Find Full Text PDFJ Med Chem
December 2024
Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, F-33607 Pessac, France.
Combining helical foldamers with α-peptides can produce α-helix mimetics with a reduced peptide character and enhanced resistance to proteolysis. Previously, we engineered a hybrid peptide-oligourea sequence replicating the N-terminal α-helical domain of p53 to achieve high affinity binding to hDM2. Here, we further advance this strategy by combining the foldamer approach with side chain cross-linking to create more constrained cell-permeable inhibitors capable of effectively engaging the target within cells.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Ludwig-Maximilians-Universitat Munchen, Pharmacy, Butenandtstraße 5 - 13, 81377, Munich, GERMANY.
Helical aromatic oligoamide foldamers bearing anionic side chains that mimic the overall shape and charge surface distribution of DNA were synthesized. Their interactions with chromosomal protein Sac7d, a non-sequence-selective DNA-binder that kinks DNA, were investigated by Surface Plasmon Resonance (SPR), Isothermal Titration Calorimetry (ITC), Circular Dichroism spectroscopy (CD), melting curve analysis, Atomic Force Microscopy (AFM), and Nuclear Magnetic Resonance (NMR), as well as by single crystal X-ray crystallography. The foldamers were shown to bind to Sac7d better than a DNA duplex of comparable length.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
October 2024
Laboratory of Organic and Physical Chemistry, Applied Bioorganic Chemistry Team, Faculty of Sciences, Ibnou Zohr University, Agadir, Morocco.
The title mol-ecule, CHBrNO, adopts a cup shaped conformation with the distinctly ruffled imidazolidine ring as the base. In the crystal, weak C-H⋯O hydrogen bonds and C-H⋯π(ring) inter-actions form helical chains of mol-ecules extending along the -axis direction that are linked by additional weak C-H⋯π(ring) inter-actions across inversion centres. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (51.
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