scholarly journals Mitochondria have Fe(III) receptors

1990 ◽  
Vol 265 (2) ◽  
pp. 415-419 ◽  
Author(s):  
J Weaver ◽  
H Zhan ◽  
S Pollack
Keyword(s):  
Recent Work ◽  
Iron Complex ◽  
Major Constituent ◽  
High Affinity ◽  
Saturable Binding ◽  
Iron Pool ◽  
New Evidence ◽  
Binding To Mitochondria

Recent work has provided new evidence that ATP is the major constituent of the low-Mr iron pool in the reticulocyte. The interaction of the iron complex of ATP with mitochondria was investigated in the present experiments. When ATP-Fe3+ was incubated with mitochondria, Fe3+, free of ATP, bound with high affinity to Fe3+ receptors on the mitochondria. The binding was saturable and reversible. Iron which was complexed to PPi, nitrilotriacetate, citrate, ADP and GTP also showed saturable binding to mitochondria; Fe3+ complexed to AMP bound non-specifically, as did Fe2+/ascorbate complexed to AMP bound non-specifically, as did Fe2+/ascorbate and Fe2+/dithionite.

scholarly journals Enhancement of iron toxicity in L929 cells by d-glucose: accelerated(re-)reduction

2002 ◽  
Vol 368 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Ilka LEHNEN-BEYEL ◽  
Herbert de GROOT ◽  
Ursula RAUEN
Keyword(s):  
Ethyl Ester ◽  
Iron Reduction ◽  
Cell Damage ◽  
Reduction Rate ◽  
Fold Increase ◽  
Iron Complex ◽  
Iron Toxicity ◽  
Intracellular Iron ◽  
Iron Valence ◽  
Iron Pool

It has recently been shown that an increase in the cellular chelatable iron pool is sufficient to cause cell damage. To further characterize this kind of injury, we artificially enhanced the chelatable iron pool in L929 mouse fibroblasts using the highly membrane-permeable complex Fe(III)/8-hydroxyquinoline. This iron complex induced a significant oxygen-dependent loss of viability during an incubation period of 5h. Surprisingly, the addition of d-glucose strongly enhanced this toxicity whereas no such effect was exerted by l-glucose and 2-deoxyglucose. The assumption that this increase in toxicity might be due to an enhanced availability of reducing equivalents formed during the metabolism of d-glucose was supported by NAD(P)H measurements which showed a 1.5—2-fold increase in the cellular NAD(P)H content upon addition of d-glucose. To assess the influence of this enhanced cellular reducing capacity on iron valence we established a new method to measure the reduction rate of iron based on the fluorescent iron(II) indicator PhenGreen SK. We could show that the rate of intracellular iron reduction was more than doubled in the presence of d-glucose. A similar acceleration was achieved by adding the reducing agents ascorbate and glutathione (the latter as membrane-permeable ethyl ester). Glutathione ethyl ester, as well as the thiol reagent N-acetylcysteine, also caused a toxicity increase comparable with d-glucose. These results suggest an enhancement of iron toxicity by d-glucose via an accelerated (re-)reduction of iron with NAD(P)H serving as central electron provider and ascorbate, glutathione or possibly NAD(P)H itself as final reducing agent.

scholarly journals New Light on the Historia Augusta

2020 ◽  
Vol 110 ◽  
pp. 167-198
Author(s):  
Justin Stover
Keyword(s):  
Recent Work ◽  
Historia Augusta ◽  
New Evidence

AbstractThis paper presents a new manuscript of part of the Historia Augusta from Erlangen, which vindicates a more than century-old hypothesis by E. Patzig: that the 1489 Venice edition of the work is textually valuable. On this basis, and building on the recent work of R. Modonutti, I present five new passages that are not printed in modern editions of the HA, six lacunose passages restored, and propose that the lost Murbach manuscript is the source. Armed with this new evidence, I re-examine the question of the great lacuna between the Lives of Maximus and Balbinus and the Lives of the Two Valerians, showing that it is a codicological — and not authorial — feature.

scholarly journals Plastic Changes in Hand Proprioception Following Force-Field Motor Learning

2010 ◽  
Vol 104 (3) ◽  
pp. 1213-1215 ◽  
Author(s):  
Daniel J. Goble ◽  
Joaquin A. Anguera
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Recent Work ◽  
Recent Article ◽  
Sensory Feedback ◽  
Motor Output ◽  
Feedback Processing ◽  
Plastic Changes ◽  
Proprioceptive Function ◽  
New Evidence

Motor neurophysiologists are placing greater emphasis on sensory feedback processing than ever before. In line with this shift, a recent article by Ostry and colleagues provided timely new evidence that force-field motor learning influences not only motor output, but also proprioceptive sense. In this Neuro Forum, the merits and limitations of Ostry and colleagues are explored in the context of recent work on proprioceptive function, including several recent studies from this journal.

Athens and Tenos in the Early Hellenistic Age

1992 ◽  
Vol 42 (2) ◽  
pp. 365-383 ◽  
Author(s):  
Gary Reger
Keyword(s):  
Recent Work ◽  
Third Century ◽  
The Third ◽  
Greek History ◽  
History Of ◽  
Old Evidence ◽  
New Evidence ◽  
Standing Problem

Some recent work on the history of Athens and Tenos in the third century B.c. has brought to light new evidence and new interpretations of old evidence for this notoriously shadowy period of Greek history. Reflection on this material has suggested to me solutions to a few minor puzzles (Sections IA, IB, III), a contribution to a long-standing problem in the history of Athens in the early third century (Section IB), and a new explanation for the entry of Rhodos into the war with Antiokhos (Section II).

Nitrogen speciation in fine and coarse clay fractions of a Cryoboroll - new evidence from pyrolysis-mass spectrometry and nitrogen K-edge XANES

2010 ◽  
Vol 90 (2) ◽  
pp. 309-318 ◽  
Author(s):  
P. Leinweber ◽  
G. Jandl ◽  
K -U. Eckhardt ◽  
J. Kruse ◽  
F L Walley ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Major Constituent ◽  
Organic N ◽  
Ionization Mass ◽  
Pyrolysis Mass Spectrometry ◽  
Edge Structure ◽  
X Ray ◽  
Soil Clay ◽  
New Evidence ◽  
X Ray Absorption

Soil clay fractions are usually enriched in nitrogen (N), but the chemical identity of this N is largely unknown. Therefore, we investigated organic N in fine and coarse clay of a clay-rich Cryoboroll by Curie-point pyrolysis-gas chromatography/mass spectrometry (Cp Py-GC/MS), Pyrolysis-field ionization mass spectroscopy (Py-FIMS) and synchrotron-based nitrogen K-edge X-ray absorption near edge structure (N-XANES) spectroscopy. The Cp Py-GC-MS revealed 30 structurally different N-containing compounds, such as substituted pyridines, pyrroles; pyrazines, pyrazoles, imidazoles, quinolines, side-chain N-containing benzenes, and single compounds of substituted benzotriazole, purine and indole. These accounted for about 10% of peak area in the Py-GC chromatograms. The Py-FIMS and N-XANES spectra indicated interlayer-NH4+ and revealed pyridinic and nitrilic N compounds, but disagreed in the proportions of pyrroles. All three complementary methods confirmed to different extents previous wet-chemical data on N-fractions in these samples, and provided new evidence for about 30 to 40% non-proteinaceous N as major constituent of the so-called “unknown organic N” in soil. Key words: Soil clay, organic matter, pyrolysis-mass spectrometry, synchrotron, X-ray absorption, NEXAFS

The Compromise of Charles Cardinal de Lorraine: New Evidence

2003 ◽  
Vol 54 (3) ◽  
pp. 469-483 ◽  
Author(s):  
STUART CARROLL
Keyword(s):  
Recent Work ◽  
Reform Movement ◽  
Privy Council ◽  
Before And After ◽  
New Evidence

The discovery of a document, until now hidden in an obscure Protestant pamphlet, presented by Charles cardinal de Lorraine (1525–74) to the privy council in August 1562, underpins recent work which shows the cardinal to have been an evangelical Catholic interested in reform and in reconciliation with Lutherans, both before and after the Colloquy of Poissy. This paper argues that Protestants feared Lorraine precisely because his interest in dialogue had the potential to split the reform movement. Publication of his five articles in 1565 was an attempt to embarrass him after Trent and to compromise his political rapprochement with the prince of Condé.

A HIGH-AFFINITY BINDING SITE FOR THE ANTIOESTROGENS, TAMOXIFEN AND CI 628, IN IMMATURE RAT UTERINE CYTOSOL WHICH IS DISTINCT FROM THE OESTROGEN RECEPTOR

1981 ◽  
Vol 91 (1) ◽  
pp. 155-161 ◽  
Author(s):  
L. C. MURPHY ◽  
R. L. SUTHERLAND
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Oestrogen Receptor ◽  
Dissociation Constants ◽  
Significant Proportion ◽  
Immature Rat ◽  
High Affinity ◽  
Saturable Binding ◽  
Receptor Sites

A high-affinity, saturable antioestrogen binding site, which does not bind oestradiol, has been reported to exist in a number of oestrogen target tissues but not in the immature rat uterus. This study reports the results of a more thorough search for this site in immature rat uterine cytosol. When concentrations of uterine cytoplasmic oestrogen receptor were selectively depleted by translocation of 90–95% of the cytoplasmic oestrogen receptor to the nucleus, saturation analysis studies revealed that the antioestrogens, tamoxifen and CI 628, were bound to high-affinity, saturable binding sites which were present at about 2·5 times the concentration of the residual oestrogen receptor sites. Oestradiol could only partially inhibit the binding of tritiated antioestrogens to their saturable binding sites in this material indicating that a significant proportion of these sites were distinct from the oestrogen receptor sites. This was confirmed in experiments where oestrogen receptor sites were saturated in vitro with oestradiol and high-affinity, saturable sites for CI 628 and tamoxifen were still present. The CI 628 and tamoxifen had high affinity for these sites with dissociation constants of 1·0–1·6 nmol/l. These specific antioestrogen binding sites were present at about 5% of the concentration of oestrogen receptors in normal immature rat uterine cytosol which probably explains their previous lack of detection in this material.

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