Ni(II) stimulates innate immunity via the direct binding to human Toll Like Receptor 4 (hTLR4), the bacterial lypopolysaccharide receptor. The binding is specific for humans and causes nickel contact allergy. The protein sequence analysis of hTLR4 revealed that the ectodomain, the region supposed to coordinate the metal ions, contains a histidine-rich motif that is not conserved among all organisms. To elucidate the role of each histidine residue on the protein-nickel binding, we examined the formation of Ni(II) complexes with the model peptide NH-FQHSNRKQMSERSVFRSRRNRIYRDISHTHTR-COO, which encompasses the sequence 429-460 of hTLR4. The amino acid sequence of the peptide has been modified by the substitution of some selected lipophilic residues (Leu and Phe) with hydrophilic residues (Arg), aiming at increasing the peptide hydro solubility of the protein fragment. Potentiometric, ultraviolet-visible (UV-vis), nuclear magnetic resonance (NMR) and circular dichroism (CD) measurements demonstrate that the non-conserved histidines in the ectodomain cooperate in metal coordination and consequently enable the activation of the molecular mechanism of nickel hypersensitivity reaction.
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http://dx.doi.org/10.1016/j.jtemb.2017.07.006 | DOI Listing |
Polymers (Basel)
January 2025
Department of Chemistry, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia.
Industrial wastewater containing heavy metal ions presents serious economic risk to the environment. In this study, a novel compound of aminated cellulose with jeffamine EDR148 was prepared to improve cellulose's adsorptive behavior towards metal ions. This study undertook a straightforward and efficient cellulose modification through homogeneous chlorination in N,N'-butylmethylimidazolium chloride to produce 6-deoxychlorocellulose (Cell-Cl), followed by a reaction with jeffamine EDR148 and ultimately resulting in the formation of aminated cellulose (Cell-Jef148).
View Article and Find Full Text PDFMetabolites
December 2024
Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, UK.
Since the biological activities and toxicities of 'foreign' and/or excess levels of metal ions are predominantly determined by their precise molecular nature, here we have employed high-resolution H NMR analysis to explore the 'speciation' of paramagnetic Ni(II) ions in human saliva, a potentially rich source of biomolecular Ni(II)-complexants/chelators. These studies are of relevance to the corrosion of nickel-containing metal alloy dental prostheses (NiC-MADPs) in addition to the dietary or adverse toxicological intake of Ni(II) ions by humans. Unstimulated whole-mouth human saliva samples were obtained from n = 12 pre-fasted (≥8 h) healthy participants, and clear whole-mouth salivary supernatants (WMSSs) were obtained from these via centrifugation.
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Chemistry, Handique Girls' College, Guwahati , 781001, Assam, India.
Context: Cation-π and cation-lone pair interactions between 3d-metal (II) ions [Fe(II), Co(II), Ni(II) and Cu(II)] and furan are explored in the formation of 1:1 and 1:2 type complexes. Both cation-π (IE = -192.27 to -312.
View Article and Find Full Text PDFNucleosides Nucleotides Nucleic Acids
January 2025
Department of PG Studies and Research in Environmental Science, Kuvempu University, Shankaraghatta, India.
This article presents a new and facile method for the synthesis of Schiff base compounds with a benzimidazole group using a low-cost and reusable calcium aluminate nanophosphorus catalyst (CaAlO). This approach avoids harmful solvents and reactants, supporting a more environmentally friendly synthesis process. The catalyst maintained its activity and heterogeneity over four cycles with minimal loss of efficiency.
View Article and Find Full Text PDFInorg Chem
January 2025
University of Göttingen, Institute of Inorganic Chemistry, Tammannstrasse 4, D-37077 Göttingen, Germany.
Alkyl nickel intermediates relevant to catalytic processes often feature agostic stabilization, but relatively little is known about the situation in oligonickel systems. The dinickel(I) complex K[LNi], which is based on a compartmental pyrazolato-bridged ligand L with two β-diketiminato chelate arms, or its masked version, the dihydride complex [KL(Ni-H)] that readily releases H, oxidatively add methyl tosylate to give diamagnetic [LNi(CH)] () with (Ni···Ni) ≈ 3.7 Å.
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