Binding of mercury in the rat kidney by metallothionein
TL;DR: Metallothionein is identified as the compound responsible for the selective binding and retention of mercury in the kidney of rats.
About: This article is published in Toxicology and Applied Pharmacology.The article was published on 1970-05-01. It has received 107 citations till now. The article focuses on the topics: Metallothionein & Sephadex.
Citations
More filters
TL;DR: The paper also touches on possible mechanisms for the "protective action" of selenium against mercury toxicity and deals briefly with the synergism between the two elements.
543 citations
Cites background from "Binding of mercury in the rat kidne..."
...It appears likely that this protein plays the part of a shielding factor against mercury, thus playing a positive role in mercury detoxification (Wisniewska et al., 1970)....
[...]
TL;DR: The identity of the proteins induced in rats by zinc, mercury and silver with the previously known metallothionein induced by cadmium has been established.
240 citations
TL;DR: This chapter discusses the differentiated state of normal and malignant cells, and the extent and the composition of the extracellular matrix is an important differentiated trait of tendon cells.
Abstract: Publisher Summary This chapter discusses the differentiated state of normal and malignant cells. The first step of cell separation (trypsinization and collagenase treatment), by removing membranous receptors and matrix elements and structures, produces a discontinuity between the cell and its environment. Thus, if the outside directs what (and how much) the cell should or should not produce, the flow of information may never be exactly the same. There are two exceptions to this. The extent and the composition of the extracellular matrix is an important differentiated trait of tendon cells. The tendon in vivo produces an extensive and organized matrix consisting primarily of collagen bundles. In the presence of ascorbic acid, these cells produce an extensive matrix also in culture. The organization of the matrix, however, is not analogous to the tendon in vivo. Both in scanning and transmission electron micrographs, the matrix appears as a mesh-like network where collagen bundles have a smaller diameter than the bundles observed in intact tendon. This may be because tendon cells in vivo are lined up in orderly arrays, while in culture they have little or no orientation especially at subconfluent stages. If cells in culture are made to line up by providing them with a preformed collagenous matrix, it may be possible to achieve an organized deposition of a de novo synthesized matrix.
218 citations
TL;DR: Repeated administration of cadmium resulted in elevation of the concentration of metallothionein both in the liver and kidney, and this was confirmed by studying the incorporation of [ 14 C]-cysteine into the metallOTHionein fraction of proteins in vivo.
194 citations
TL;DR: It was concluded that Cd, Zn-thionein exists mainly as a random-coil peptide and as a model compounds for high-molecular-weight and water-soluble cysteine compounds, respectively.
Abstract: The preparation of pure metallothionein from Cd-pretreated rats and chicken was performed using short-time treatment with chloroform/ethanol followed by ion-exchange and gel chromatography. The protein contained 7 g-atoms metal ions per 12000 g protein. The Zn to Cd ratio was 1:2.4 ± 0.1. The Cd, Zn-thionein remained homogeneous during Sephadex G-25, G-50 and G-75 gel filtration, during polyacrylamide disc-gel electrophoresis and in the analytical ultracentrifuge. The high content of cysteine residues (approx. one-third of the total residues) was consistent with the cysteine content of metallothionein isolated from human or equine tissues. The Cd, Zn-thionein was of considerable temperature stability. The physicochemical properties were examined by ultraviolet spectroscopy, circular dichroism (CD) measurements and X-ray photoelectron spectroscopy. The millimolar absorption coefficient of the native protein was at 250 nm ɛ250= 80.6 mM−1· cm−1. Virtually no aromatic amino acids were present. The ɛ250 value of the apoprotein prepared by metal displacement using HCl was ɛ250= 13.2 mM−1· cm−1. When the ultraviolet spectrum of the apoprotein was recorded at pH 6.6 a distinct peak was detectable at 255 nm (ɛ250= 18.7 m M−1· cm−1). The existence of inter- or intramolecular disulphide formation was confirmed by CD measurements employing the polyethyleneglycol esters of di-tert-butyloxy-carbonyl-l-cystine and tert-butyloxycarbonyl-l-cysteine as model compounds for high-molecular-weight and water-soluble cysteine compounds, respectively.
From CD data it was concluded that Cd, Zn-thionein exists mainly as a random-coil peptide. Some indication of the binding of Cd and Zn in the native protein with ⊖S–R moieties was obtained from ultraviolet data. Final proof of the exclusive coordination of these metal ions with cysteine sulphur was successful using both circular dichroism measurements and especially X-ray photo-electron spectroscopy. The last method proved most convenient for determining the binding energies of the core electrons of Cd (Cd 3d3/2= 411.0 eV and Cd 3d5/2= 404.4 eV), Zn (2 p3/2= 1021.0 eV) and S (2p = 161.7 eV). The corresponding binding energies for S in the cystine complexes with Zn2+ and Cd2+ were 163.0 eV and 162.8 eV, respectively.
176 citations
References
More filters
Journal Article•
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
289,852 citations
TL;DR: The results are similar to those of previous studies, where the objective was to establish a cause-and-effect relationship, rather than a straightforward relationship between the number of cells and the content of the molecule.
Abstract: Allen, R. J. L. (1940). Biochem. J. 34, 858. Bartlett, P. D., Grimmett, P., Beers, L. & Shelata, S. (1956). J. biol. Chem. 218, 419. Burton, K. (1956). Biochem. J. 62, 315. Caiger, P., Morton, R. K., Jarrett, I. G. & Filsell, 0. H. (1962). Biochem. J. 85, 351. Filsell, 0. H., Jarrett, I. G., Atkinson, M. R., Caiger, P. & Morton, R. K. (1963). Biochem. J. 89, 92. Fishkin, A. F. & Lata, G. F. (1958). Endocrinology, 63, 162. Franz, J. M. & Lata, G. F. (1957). Endocrinology, 60, 602. Gallagher, C. H. (1959). Au8t. J. agric. Res. 10, 854. Gallagher, C. H. & Buttery, S. H. (1959). Biochem. J. 72, 575. Handschumacher, R. E., Mueller, G. C. & Strong, F. M. (1951). J. biol. Chem. 189, 335. Holdsworth, E. S., Neville, E., Nader, C., Jarrett, I. G. & Filsell, 0. H. (1963). Biochim. biophy8. Acta (in the Press). Jarrett, I. G. & Filsell, 0. H. (1958). Aust. J. exp. Biol. med. Sci. 36, 433. Jarrett, I. G. & Filsell, 0. H. (1960). Aust. J. exp. Biol. med. Sci. 38, 347. Jarrett, I. G., Jones, G. B. & Potter, B. J. (1964). Biochem. J. 90, 189. Jarrett, I. G. & Potter, B. J. (1952). Au8t. J. exp. Biol. med. Sci. 30, 207. Kaplan, N. 0. & Lipmann, F. (1948). J. biol. Chem. 174,37. Klein, H. & Lipmann, F. (1953). J. biol. Chem. 203, 101. Krebs, H. A. & Kornberg, H. L. (1957). Ergebn. Physiol. 49, 212. McCandless, E. L. & Dye, J. A. (1950). Amer. J. Physiol. 162, 434. McCarthy, R. D., Shaw, J. C. & Lakshmanan, S. (1958). Proc. Soc. exp. Biol., N. Y., 99, 560. McLean, P. (1958). Biochim. biophys. Acta, 30, 303. Novelli, G. D. (1953). Phy8iol. Rev. 33, 525. Olson, R. E. & Kaplan, N. 0. (1948). J. biol. Chem. 175, 515 Schneider, W. C. (1945). J. biol. Chem. 161, 293. Thompson, M. & Mayer, J. (1962). Amer. J. Physiol. 202, 1005.
3,756 citations
TL;DR: Correlation between elution volume, V(e), and molecular weight was investigated for gel filtration of proteins of molecular weights ranging from 3500 (glucagon) to 820000 (alpha-crystallin) on Sephadex G-200 columns at pH7.5.
Abstract: 1. Correlation between elution volume, V(e), and molecular weight was investigated for gel filtration of proteins of molecular weights ranging from 3500 (glucagon) to 820000 (alpha-crystallin) on Sephadex G-200 columns at pH7.5. 2. Allowing for uncertainties in the molecular weights, the results for most of the carbohydrate-free globular proteins fitted a smooth V(e)-log(mol.wt.) curve. In the lower part of the molecular-weight range the results were similar to those obtained with Sephadex G-75 and G-100 gels. 3. V(e)-log(mol.wt.) curves based on results with the three gels are taken to represent the behaviour of ;typical' globular proteins, and are proposed as standard data for the uniform interpretation of gel-filtration experiments. 4. Some glycoproteins, including gamma-globulins and fibrinogen, do not conform to the standard relationship. The effect of shape and carbohydrate content on the gel-filtration behaviour of proteins is discussed. 5. As predicted by the theoretical studies of other authors, correlation exists between the gel-filtration behaviour and diffusion coefficients of proteins. 6. The lower molecular-weight limit for complete exclusion of typical globular proteins from Sephadex G-200 varies with the swelling of the gel, but is usually >10(6). 7. The concentration-dependent dissociation of glutamate dehydrogenase was observed in experiments with Sephadex G-200, and the sub-unit molecular weight estimated as 250000. The free sub-units readily lose enzymic activity. 8. Recognition of the atypical gel-filtration behaviour of gamma-globulins necessitates an alteration to several molecular weights previously estimated with Sephadex G-100 (Andrews, 1964). New values are: yeast glucose 6-phosphate dehydrogenase, 128000; bovine intestinal alkaline phosphatase, 130000; Aerobacter aerogenes glycerol dehydrogenase, 140000; milk alkaline phosphatase, 180000.
2,830 citations
881 citations
634 citations