Analytical application of particle induced X-ray emission

Johansson, Sven; Johansson, Thomas B.

doi:10.1016/0029-554x(76)90470-5

Cited by 620 publications

(100 citation statements)

References 149 publications

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“…The isolated polypeptides did not contain any metals, as determined with particle-induced X-ray emission [20] or other cofactors with absorption in the visible region of the spectrum.…”

Section: Isolation Of the 22-kda And The Io-kda Polypeptidesmentioning

confidence: 94%

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Isolation and characterization of the 10‐kDa and 22‐kDa polypeptides of higher plant photosystem 2

Ljungberg

Åkerlund

Andersson

1986

European Journal of Biochemistry

134

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Two polypeptides of 10 kDa and 22 kDa, shown to be components of the higher plant photosystem 2, were purified and examined. A NaCl/Triton X-100 treatment was designed, which released these two polypeptides from the thylakoid membrane, in concert with the extrinsic 16-kDa and 23-kDa proteins, concomitant with a loss in oxygen-evolution activity. After this treatment the oxygen-evolving activity of the photosystem 2 membranes devoid of the 10-kDa and the 22-kDa polypeptides could be restored with CaC12, but not by readdition of the purified 23-kDa protein. This defiency was caused by an inability of the 23-kDa protein to rebind to the photosystem 2 membranes. In analogy, the oxygen-evolution activity of a highly purified photosystem 2 core preparation, devoid of the 10-kDa and 22-kDa polypeptides, was stimulated by CaC12, but not by the 23-kDa protein. We, therefore, suggest that the 1 0-kDa or the 22-kDa polypeptides provide a binding-site for the extrinsic 23-kDa protein to the thylakoid membrane.The 1 0-kDa and 22-kDa polypeptides were isolated through ion-exchange chromatography in the presence of detergents. They both displayed hydrophobic properties, verified by their low proportion of polar amino acid residues and their partition to the hydrophobic phase during Triton X-114 fractionation. The purified polypeptides did not contain metallic cofactors or substances with absorption in the visible region of the spectrum.In recent years extensive knowledge about biophysics, biochemistry and molecular biology of higher plant photosystem 2 has accumulated (reviewed in [l -31). The present concept of the photosystem 2 is of a supramolecular complex, with both integral and peripheral protein subunits, mainly located in the grana region of the thylakoid membrane. A number of studies have indicated that the catalytic photosystem 2 core complex is made up of at least five different hydrophobic proteins [4 -61 and a number of low-molecular-mass polypeptides [7]. In addition extrinsic proteins of 33 kDa, 23 kDa and 16 kDa have been shown to be located at the inner thylakoid surface and to be regulatory components of the oxygen-evolving complex of photosystem 2. The 33-kDa protein seems to have a stabilizing effect on the catalytic manganese, while the 23-kDa and the 16-kDa proteins are involved in the binding of the calcium and chloride necessary for oxygen evolution [2].In an immunoprecipitation study we have previously shown that a close structural association exists between the 33-kDa and 23-kDa proteins, and three polypeptides of 10 kDa, 22 kDa and 24 kDa [8]. Furthermore, the 10-kDa polypeptide was found to be released from everted photosystem 2 membranes by alkaline Tris [9], a treatment which inhibits oxygen evolution. A nearest-neighbor analysis, using chemical cross-linking, also revealed a close proximity between the 33-kDa protein and 22-kDa and 24-kDa polypeptides [lo].In the present study we report the isolation and chardcterization of the two polypeptides of 10 kDa and 22 kDa. MATERIALS AND METHODS Sub-thy...

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“…The isolated polypeptides did not contain any metals, as determined with particle-induced X-ray emission [20] or other cofactors with absorption in the visible region of the spectrum.…”

Section: Isolation Of the 22-kda And The Io-kda Polypeptidesmentioning

confidence: 94%

“…Protein concentration were determined according to Lowry et al [19] in the presence of 3.3% sodium dodecyl sulphate. Metal analysis of protein fractions was performed by particle-induced X-ray emission [20]. Triton X-l14/water phase partitioning [21] was performed as in [22].…”

Section: Protein Purificationmentioning

confidence: 99%

Isolation and characterization of the 10‐kDa and 22‐kDa polypeptides of higher plant photosystem 2

Ljungberg

Åkerlund

Andersson

1986

European Journal of Biochemistry

134

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“…If a proton microprobe is used, this problem is more serious. Higher proton energies will be helpful to increase the X-ray yield [5]. To reduce the necessary exposure time dramatically, one needs not only a dedicated high-current proton accelerator, but also an innovative focusing technique that works well under strong space-charge effect of intense proton beams.…”

Section: Discussionmentioning

confidence: 99%

“…The energy of the X-rays emitted when the vacancies are refilled is characteristic for the element from which they originate. This phenomenon is known as a tool for elemental analysis, where spectra of the characteristic X-rays emitted from the sample are measured to identify and quantify the trace elements contained in the sample [5]. If one uses an electron beam instead of the proton beam, as in the case of ordinary X-ray tubes, the energy spectrum of the X-rays is degraded by a continuum [6], because of the high Bremsstrahlung background resulting from the strong deceleration of incident electrons.…”

Section: Introductionmentioning

confidence: 99%

Imaging by using proton-induced quasi-monochromatic X-ray emission

Iwatani¹,

Kaneko²,

Hasegawa³

et al. 2004

Science and Technology of Advanced Materials

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Quasi-monochromatic X-ray emission induced by MeV-proton bombardment onto metallic targets was applied to radiography of small samples. The X-ray energy was adjusted in the range of z4-23 keV by changing the target material. The radiograms were recorded on an imaging plate. A small phantom made of Lucite was prepared for the test of photography using a contrast medium (RuCl 3 $H 2 O; ruthenium chloride). To clearly observe the image of the contrast agent, the photon energy was chosen to be 23.17 keV (Cd Ka) which is slightly above the K-absorption edge of Ru at 22.12 keV. Only the image of the contrast agent was successfully extracted by subtracting the image taken by 21.18-keV X-rays (Pd Ka) from that obtained by the 23.17-keV photons. Also images of a small fish sample were taken using a point-like X-ray source excited by a proton microbeam with a diameter of z10 mm. In this experiment, the X-ray energy was adjusted to 4.51 keV (Ti Ka) to obtain a strong attenuation by Ca in the bones. A fine structure of the bones in the thin caudal fin (!100 mm) was highly contrasted by this method. The spatial resolution of the picture was z20 mm. Performance of the above technique based on the proton-induced quasimonochromatic X-ray emission is discussed in comparison to conventional methods. q

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“…Because the background noise of the characteristic X -ray employed by micro -PIXE is approximately two orders of magnitude lower than that used in EPM� (Reuter et al, 1975;Johansson and Johansson, 1976), PIXE is one of the most powerful tools in measuring geologically important elements at ppm -level sensitivity (Campbell et al, 1990;Ryan et al, 1990). Quantitative two -dimensional (2 -D) elemental images were obtained via Dynamic �nalysis (Ryan et al., 1995), which is an analytical method for projecting quantitative element images from PIXE.…”

Section: Analytical Proceduresmentioning

confidence: 99%

Quantitative micro-PIXE analysis of heavy-metal-rich framboidal pyrite

Sugawara

Sakakibara

Belton

et al. 2008

Journal of Mineralogical and Petrological Sciences

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Framboidal pyrite in mudstone is known to be a reservoir of arsenic, yet few studies have conducted quantitative analyses of framboidal pyrite with ppm -level sensitivity. In this study, we used micro -PIXE to measure the concentrations of heavy metals in framboidal pyrite from drill -core samples of mudstone from the Late Cretaceous Hakobuchi Group, central Hokkaido, Japan. Pyrite framboids that occur in polyframboids can be divided into two types based on framboid diameter (D) and the average diameter of microcrystals within framboids (d): type 1, being relatively small grains; and type 2, being relatively large grains. Higher concentrations of �s are Higher concentrations of �s are Higher concentrations of �s are observed in most type 2 framboids than in type 1 framboids. High concentrations of Pb generally occur as isolated islands within type 1 framboids, concentrated along the rims of polyframboids. It could be concluded that contrasting formation processes among different framboids led to the observed changes in heavy metal concentrations.

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Analytical application of particle induced X-ray emission

Cited by 620 publications

References 149 publications

Isolation and characterization of the 10‐kDa and 22‐kDa polypeptides of higher plant photosystem 2

Isolation and characterization of the 10‐kDa and 22‐kDa polypeptides of higher plant photosystem 2

Imaging by using proton-induced quasi-monochromatic X-ray emission

Quantitative micro-PIXE analysis of heavy-metal-rich framboidal pyrite

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