Transmission Electron Microscopy (TEM), X-ray Absorption Near Edge Spectroscopy (XANES), Energy-Loss (EELS), Small-Angle Scattering (SAXS), and SQUID magnetic studies were performed in a batch of horse spleen ferritins from which iron had been gradually removed, yielding samples containing 2200, 1200, 500, 200 atoms. Taken together, findings obtained demonstrate that the ferritin core consists polyphasic structure (ferrihydrite, magnetite, hematite) proportion phases is modified by removal....

A new approach for the preparation of carbohydrate-coated magnetic nanoparticles is reported. In a first step, we show that pH-driven assembly-disassembly natural process occurs in apoferritin protein effective encapsulation maghemite different sizes: 4 and 6 nm. second demonstrate presence functional amine groups outer shell allows functionalization with two carbohydrates, N-acetyl-d-glucosamine d-mannose. High-resolution electron microscopy (HREM), high angle annular dark field scanning...

An electron microscopy study, in combination with modeling and image simulation, of four different reconstituted ferritin samples: recombinant human H L homopolymers, heteropolymers native L-subunit-rich horse spleen H-subunit-rich heart ferritins, points out the existence a correlation between iron core shape protein shell.

Biogenic magnetite is a fascinating example of how nature can generate functional magnetic nanostructures. Inspired by the bacteria, an attempt made to mimic their properties, rather than structures, create living magnets at room temperature. The non‐magnetic probiotic bacteria Lactobacillus fermentum and Bifidobacteria breve are used as bioplatforms densely arrange superparamagnetic nanoparticles on external surfaces, thus obtaining artificial bacteria. Magnetic be produced using maghemite...

Binding of anions great environmental concern such as SO(4)(2-), PO(4)(3-), AsO(4)(3-), HgCl(4)(2-), and CrO(4)(2-) by the protonated forms a tren-like (tren = tris(2-aminoethyl)amine) ligand (HL) functionalized with pyrimidine residue was studied means potentiometric measurements isothermal titration calorimetry (ITC) affording log K, ΔH°, TΔS° values for formation relevant complexes. The complexes show high to very stability due particular topology electronic properties which is able use...

The results presented in this work are related to the design of a guideline develop specific properties at surface an activated carbon (AC). For this, two model aromatic compounds have been synthesized and their electrolytic behavior aqueous solutions was studied by potentiometric method. textural characteristics were determined porosimetry methods. nature oxygen-carrying functions acid-base AC characterized TPD titration methods, respectively. adsorption desorption equilibria on measured...

Ferritin, a soluble and highly robust protein with subunits packed into well-defined helices, is key component of the iron regulatory system in brain thus widely recognized as crucial for metabolism, but may also bear possible implications some neurodegenerative disorders. Here, we present evidence how human recombinant apoferritin can convert an unusual structure from its folded native state; that is, amyloid fibrils analogue to those found pathological disorders such Alzheimer's...

The release of iron from ferritin by aceto- and benzohydroxamic acids was studied at two different chelator concentrations (100 10 mM), pH values (7.4 5.2), in the presence or absence urea. Collectively, results demonstrate that both remove ferritin. Aceto- penetrate shell react directly with core cavity probably forming mono(hydroxamate) iron(III) complexes which exit excess hydroxamate solution to produce bis(hydroxamate) complexes. sizes acid mono(benzohydroxamate) complex, 6 7 Å,...

The adsorption of five Nα-substituted amino acids with a 5-nitroso-6-oxo pyrimidine as substituent on commercial activated carbon (AC) has been studied in aqueous solution at several pH values. processes these organic compounds have analyzed the basis electrolytic behavior adsorbates. In all cases, process is highly irreversible due to strong π−π interactions between arene centers AC and residue This interaction consistent XPS data HOMO−LUMO theoretical calculations. provides new route for...

Abstract A new class of water‐soluble, fluorescent, magnetic quantum dots––magnetoferritin bioconjugate––is prepared. The nanostructures are patterned mainly as dimer particles characterized by high‐angle annular dark‐field scanning transmission electron microscopy and energy loss spectroscopy. Magnetic (high spontaneous magnetization values, superparamagnetism) fluorescent (narrow emission peaks, uniform brightness) properties both nanoblocks maintained in the final nanostructure.

A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, water at room temperature, of macrocyclic H2L ligand on graphene (G) (G + = G-(H2L)), followed by decoration macrocycle with Pd2+ ions (G-(H2L) G-(H2L)-Pd) under same mild conditions. This supramolecular approach is sustainable (green) procedure that preserves special characteristics and furnishes an efficient for Cu-free Sonogashira cross coupling reaction between...

Recently, research in the field of protein amyloid fibers has gained great attention due to use these materials as nanoscale templates for construction functional hybrid materials. The formation apoferritin amyloid-like is demonstrated herein first time. morphology, size and stiffness one-dimensional structures are comparable formed by β-lactoglobulin, a frequently used model study fibrillar proteins. Nanometer-sized globular capable self-assembling form 1D micrometer-sized after being...

The reaction of cis-[MCl(2)(dppm)] (M = Pt(II) and Pd(II); dppm bis(diphenylphosphino)methane) with H(2)TT NaOH (H(2)TT 8-thiotheophylline) yields neutral mononuclear [M(HTT-S(8))(2)(dppm)] complexes. Homodinuclear [M(&mgr;-TT-N(7),S(8))(dppm)](2) Pd(II)) are prepared either by the [M(HTT)(2)(dppm)] or direct Na(2)TT, in situ from NaOH. crystal structure Pt derivative is reported: [Pt(&mgr;-TT)(dppm)](2).2DMSO (3) crystallizes triclinic space group P&onemacr; a 12.949(3) Å, b 13.009(3) c...

Abstract The compound N ‐(4‐amino‐1‐methyl‐5‐nitroso‐6‐oxo‐1,6‐di‐hydropyrimidin‐2‐yl)‐ '‐[bis(2‐aminoethyl)]ethylenedi‐amine (HL) was synthesised and structurally characterised by analytical methods 1 H, 13 C 15 NMR spectroscopy. protonation of HL its coordinating ability towards Zn 2+ Cd ions in water solution were also studied potentiometric UV/Visible H‐ molecular structures [H 3 L] [CdI 4 ] 2– · 2H 2 O [(Cl Zn)(μ‐Cl){Zn(μ ‐HL)}] 2.5H solved single‐crystal X‐ray diffraction methods. On...

The reaction of [(AuBr)(2)(&mgr;-PR(2)P(CH(2))(n)()PR(2))] (where R = CH(3) for n 1; Ph 1, 3, 4) with N-alkylxanthine and thioxanthine derivatives, containing two ionizable protons in close positions, yields, under basic conditions, neutral heterobridged dinuclear gold(I) ring complexes [Au(&mgr;-L)(2)(&mgr;-PR(2)P(CH(2))(n)()PR(2))], which have been investigated by means (1)H- (31)P-NMR FAB spectroscopies. Crystal structures these are reported. [Au(2)(&mgr;-HX)(&mgr;-dmpe)].3H(2)O (1)...

Abstract Iron metabolism is an important subject of study for undergraduate students chemistry and biochemistry. Relevant laboratory exercises are scarce in the literature but would be very helpful assisting grasp key concepts. The experiment described here deals with different iron release mechanisms two protagonists metabolism: serum transferrin (Tf) lactoferrin (Lf). Despite having similar structures iron‐binding sites, Tf releases practically all its at pH 5.5 while Lf requires a...

A novel symmetrical bis-tetradentate Schiff base, H4L, has been prepared from the condensation of H2L′[N,N′-bis(3-aminopropyl)oxamide] with imidazole-2-carbaldehyde. This ligand reacts copper(II) perchlorate in neutral medium to yield dinuclear complex [Cu2(H2L)][ClO4]2, which two non-deprotonated imidazolyl moieties. The crystal structure this compound, solved by single-crystal X-ray diffraction, consists planar centrosymmetric cations and anions. ions are bridged an oxamidate group trans...