X-ray Characterization of Conformational Changes of Human Apo- and Holo-Transferrin

Human serum transferrin (Tf) is a bilobed glycoprotein whose function is to transport iron through receptor-mediated endocytosis. The mechanism for iron release is pH-dependent and involves conformational changes in the protein, thus making it an attractive system for possible biomedical applications. In this contribution, two powerful X-ray techniques, namely Macromolecular X-ray Crystallography (MX) and Small Angle X-ray Scattering (SAXS), were used to study the conformational changes of iron-free (apo) and iron-loaded (holo) transferrin in crystal and solution states, respectively, at three different pH values of physiological relevance. A crystallographic model of glycosylated apo-Tf was obtained at 3.0 Å resolution, which did not resolve further despite many efforts to improve crystal quality. In the solution, apo-Tf remained mostly globular in all the pH conditions tested; however, the co-existence of closed, partially open, and open conformations was observed for holo-Tf, which showed a more elongated and flexible shape overall.

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SAXS characterization of the interactions among digested food compounds and the anti-oxidant and anti-inflammatory activities of the formed nanocomplexes

Food & Function ◽

10.1039/c8fo00563j ◽

2018 ◽

Vol 9 (6) ◽

pp. 3408-3418 ◽

Cited By ~ 1

Author(s):

Yingkang Yang ◽

Xiaoqi Wang ◽

Guijie Chen ◽

Wenhua Zhou ◽

Xiaoxiong Zeng ◽

...

Keyword(s):

Small Angle ◽

X Ray ◽

X Ray Scattering ◽

Anti Oxidant ◽

Ph Conditions ◽

Anti Inflammatory ◽

Ray Scattering

Small angle X-ray scattering (SAXS) is applied to investigate the interaction between caseinophosphopeptides (CPP) and chitosan (CS) under simulated gastrointestinal (GI) pH conditions.

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A simple adaptation to a protein crystallography station to facilitate difference X-ray scattering studies

Journal of Applied Crystallography ◽

10.1107/s1600576719001900 ◽

2019 ◽

Vol 52 (2) ◽

pp. 378-386

Author(s):

Amit Sharma ◽

Peter Berntsen ◽

Rajiv Harimoorthy ◽

Roberto Appio ◽

Jennie Sjöhamn ◽

...

Keyword(s):

Conformational Changes ◽

Flow Cell ◽

Infrared Lasers ◽

X Ray ◽

X Ray Crystallography ◽

X Ray Scattering ◽

Caged Calcium ◽

Beam Stop ◽

Waxs Data ◽

Ray Scattering

The X-ray crystallography station I911-2 at MAXLab II (Lund, Sweden) has been adapted to enable difference small- and wide-angle X-ray scattering (SAXS/WAXS) data to be recorded. Modifications to the beamline included a customized flow cell, a motorized flow cell holder, a helium cone, a beam stop, a sample stage and a sample delivery system. This setup incorporated external devices such as infrared lasers, LEDs and reaction mixers to induce conformational changes in macromolecules. This platform was evaluated through proof-of-principle experiments capturing light-induced conformational changes in phytochromes. A difference WAXS signature of conformational changes in a plant aquaporin was also demonstrated using caged calcium.

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Small angle X-ray scattering study of porosity variation in a styrene-divinylbenzene copolymer

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19811675 ◽

1981 ◽

Vol 46 (7) ◽

pp. 1675-1681 ◽

Cited By ~ 13

Author(s):

Josef Baldrian ◽

Božena N. Kolarz ◽

Henrik Galina

Keyword(s):

Small Angle ◽

Structural Parameters ◽

Two Phase ◽

X Ray ◽

Porosity Variation ◽

Swelling Agent ◽

X Ray Scattering ◽

Styrene Divinylbenzene ◽

Ray Scattering

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.

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Mn-Mo-O Catalysts for Methanol Oxidation. I. Preparation and Characterization of the Catalysts

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19922529 ◽

1992 ◽

Vol 57 (12) ◽

pp. 2529-2538 ◽

Cited By ~ 3

Author(s):

Krasimir Ivanov ◽

Penka Litcheva ◽

Dimitar Klissurski

Keyword(s):

Methanol Oxidation ◽

Solution Concentration ◽

Alkaline Media ◽

Acidic Media ◽

Chemical Methods ◽

X Ray ◽

Ph Values ◽

Precipitate Composition

Mn-Mo-O catalysts with a different Mo/Mn ratio have been prepared by precipitation. The precipitate composition as a function of solution concentration and pH was studied by X-ray, IR, thermal and chemical methods. Formation of manganese molybdates with MnMoO4.1.5H2O, Mn3Mo3O12.2.5H2O, and Mn3Mo4O15.4H2O composition has been supposed. It is concluded that pure MnMoO4 may be obtained in both acid and alkaline media, the pH values depending on the concentration of the initial solutions. The maximum Mo/Mn ratio in the precipitates is 1.33. The formation of pure Mn3Mo4O15.4H2O is possible in weakly acidic media. This process is favoured by increasing the concentration of initial solutions.

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First characterization of chemical environments using energy dispersive inelastic x-ray scattering induced by an x-ray tube

Review of Scientific Instruments ◽

10.1063/5.0026061 ◽

2021 ◽

Vol 92 (1) ◽

pp. 013102

Author(s):

Roberto Daniel Pérez ◽

Juan José Leani ◽

José Ignacio Robledo ◽

Héctor Jorge Sánchez

Keyword(s):

Energy Dispersive ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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Effect of tungsten disulfide nanotubes on crystallization of polylactide under uniaxial deformation and annealing

Functional Composite Materials ◽

10.1186/s42252-021-00016-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Fausta Loffredo ◽

Loredana Tammaro ◽

Tiziana Di Luccio ◽

Carmela Borriello ◽

Fulvia Villani ◽

...

Keyword(s):

Biomedical Applications ◽

Structural Evolution ◽

Tungsten Disulfide ◽

Fine Tuning ◽

Nanocomposite Films ◽

Uniaxial Deformation ◽

Scanning Calorimetry ◽

X Ray ◽

X Ray Scattering

AbstractTungsten disulfide (WS2) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS2 nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS2 nanocomposite films varying the concentration of WS2 NTs from 0 (neat PLA) to 0.6 wt%. The films were uniaxially drawn at 90 °C and annealed at the same temperature for 3 and 10 min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS2 NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6 wt% of WS2 induces the same level of crystallinity in as stretched PLA-WS2 as annealing in neat PLA for 10 min. These data provide useful insights into the role of WS2 NTs on the structural evolution of PLA-WS2 composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.

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Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

Journal of Chemical Crystallography ◽

10.1007/s10870-021-00891-4 ◽

2021 ◽

Author(s):

Shabana Noor ◽

Richard Goddard ◽

Fehmeeda Khatoon ◽

Sarvendra Kumar ◽

Rüdiger W. Seidel

Keyword(s):

Molecular Structure ◽

Schiff Base ◽

Structural Characterization ◽

Schiff Base Ligand ◽

Crystal And Molecular Structure ◽

X Ray ◽

X Ray Crystallography ◽

Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

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Nanostructural Characterization of Oleyl Acid Phosphate in Poly-α-olefin Using Small-angle X-ray Scattering

Chemistry Letters ◽

10.1246/cl.200204 ◽

2020 ◽

Vol 49 (7) ◽

pp. 823-825

Author(s):

Yojiro Oba ◽

Ryuhei Motokawa ◽

Masahiro Hino ◽

Nozomu Adachi ◽

Yoshikazu Todaka ◽

...

Keyword(s):

Small Angle ◽

Acid Phosphate ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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Preparation and structural analysis of (±)-threo-ritalinic acid

Acta Crystallographica Section C Crystal Structure Communications ◽

10.1107/s010827011302595x ◽

2013 ◽

Vol 69 (11) ◽

pp. 1225-1228 ◽

Cited By ~ 2

Author(s):

Sara Wyss ◽

Irmgard A. Werner ◽

W. Bernd Schweizer ◽

Simon M. Ametamey ◽

Selena Milicevic Sephton

Keyword(s):

Methyl Ester ◽

Free Acid ◽

Nmr Analysis ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

X Ray Crystallography ◽

Ph Values ◽

Ritalinic Acid ◽

Methyl Phenidate ◽

Hydrolysis Of

Hydrolysis of the methyl ester (±)-threo-methyl phenidate afforded the free acid in 40% yield,viz.(±)-threo-ritalinic acid, C13H17NO2. Hydrolysis and subsequent crystallization were accomplished at pH values between 5 and 7 to yield colourless prisms which were analysed by X-ray crystallography. Crystals of (±)-threo-ritalinic acid belong to theP21/nspace group and form intermolecular hydrogen bonds. An antiperiplanar disposition of the H atoms of the (HOOC—)CH—CHpygroup (py is pyridine) was found in both the solid (diffraction analysis) and solution state (NMR analysis). It was also determined that (±)-threo-ritalinic acid conforms to the minimization of negativegauche+–gauche−interactions.

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