Lead inhibits 1,25-dihydroxyvitamin D-3 regulation of calcium metabolism in osteoblastic osteosarcoma cells (ROS 17/2.8).
AuthorsSchanne FA, Gupta RK, Rosen JF
JournalBiochim Biophys Acta
PubMed ID1463769
We have determined the dose-response of 1,25-dihydroxyvitamin D-3 (1,25-(OH)2D3) on the intracellular free calcium-ion concentration ([Ca2+]i) in the osteoblastic osteosarcoma cells, ROS 17/2.8, using 19F-NMR and the intracellular divalent cation indicator, 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (5F-BAPTA). The dose-response demonstrated an inverted U-shaped relationship with maximal elevation of [Ca2+]i at doses of 1 ... More
Effect of the two conserved prolines of human growth inhibitory factor (metallothionein-3) on its biological activity and structure fluctuation: comparison with a mutant protein.
AuthorsHasler DW, Jensen LT, Zerbe O, Winge DR, Vasák M
JournalBiochemistry
PubMed ID11087412
'Human neuronal growth inhibitory factor, a metalloprotein classified as metallothionein-3 (MT-3), impairs the survival and the neurite formation of cultured neurons. In these studies the double P7S/P9A mutant (mutMT-3) and single mutants P7S and P9A of human Zn(7)-MT-3 were generated, and their effects on the biological activity and the structure ... More
NMR studies of the effect of hyperglycemia on intracellular cations in rat kidney.
AuthorsDowd TL, Gupta RK
JournalJ Biol Chem
PubMed ID8419377
'Alterations in intracellular cation concentrations in the kidney during hyperglycemia may play a role in a number of complications associated with diabetes mellitus such as renal hypertrophy and hypertension. In this study, we have investigated the effect of 25 mM glucose on intracellular pH and free Mg2+, free Ca2+, and ... More
Calcium buffer injections block fucoid egg development by facilitating calcium diffusion.
AuthorsSpeksnijder JE, Miller AL, Weisenseel MH, Chen TH, Jaffe LF
JournalProc Natl Acad Sci U S A
PubMed ID2505254
'The polarity of fucoid eggs is fixed either when tip growth starts or a bit earlier. A steady flow of calcium ions into the incipient tip is thought to establish a high calcium zone that is needed for its localization and formation. To test this hypothesis, we have injected seven ... More
Cell-permeant Ca2+ chelators reduce early excitotoxic and ischemic neuronal injury in vitro and in vivo.
AuthorsTymianski M, Wallace MC, Spigelman I, Uno M, Carlen PL, Tator CH, Charlton MP
JournalNeuron
PubMed ID8102532
'We report the characterization of the first successful treatment of neuronal ischemic injury in vivo by cell-permeant Ca2+ chelators. The chelators attenuated glutamate-induced intracellular Ca2+ increases and neurotoxicity in neuronal explant cultures. When infused intravenously in rats, permeant fluorescent BAPTA analogs accumulated in neurons in several brain regions. BAPTA-AM, infused ... More
Local positive feedback by calcium in the propagation of intracellular calcium waves.
AuthorsWang SS, Thompson SH
JournalBiophys J
PubMed ID8580312
'In many types of eukaryotic cells, the activation of surface receptors leads to the production of inositol 1,4,5-trisphosphate and calcium release from intracellular stores. Calcium release can occur in complex spatial patterns, including waves of release that traverse the cytoplasm. Fluorescence video microscopy was used to view calcium waves in ... More
Calcium mobilization is required for nuclear vesicle fusion in vitro: implications for membrane traffic and IP3 receptor function.
AuthorsSullivan KM, Busa WB, Wilson KL
JournalCell
PubMed ID8391933
'We studied the fusion of nuclear vesicles bound to chromatin in Xenopus egg extracts. Fusion was inhibited by 5 mM BAPTA, a Ca2+ buffer that suppresses cytosolic [Ca2+] gradients. The BAPTA-inhibited step in fusion was biochemically distinct from, and occurred later than, the GTP gamma S-sensitive step mediated by the ... More
A continuous spectrophotometric assay for simultaneous measurement of calcium uptake and ATP hydrolysis in sarcoplasmic reticulum.
AuthorsKaron BS, Nissen ER, Voss J, Thomas DD
JournalAnal Biochem
PubMed ID7573954
'A continuous, spectrophotometric assay to simultaneously measure Ca uptake and ATP hydrolysis has been developed, in order to assess the function of the Ca-ATPase in skeletal and cardiac sarcoplasmic reticulum (SR) vesicles. The absorbance of Fura Red was measured continuously at 490 nm, in EGTA-buffered solutions containing initial free ionized ... More
On the dissociation constants of BAPTA-type calcium buffers.
AuthorsPethig R, Kuhn M, Payne R, Adler E, Chen TH, Jaffe LF
JournalCell Calcium
PubMed ID2515001
'We have determined or redetermined the calcium dissociation constants of seven BAPTA-type buffers with KD''s in the range from 0.4 microM to about 20 mM in 300 mM KCl. These include four newly synthesized ones: 5-nitro BAPTA; 5,5''-dinitro BAPTA; 5-methyl-5''-nitro BAPTA; and 5-methyl-5''-formyl BAPTA. Moreover, we tabulate dissociation constants or ... More
The physical mechanism of calcium pump regulation in the heart.
AuthorsVoss J, Jones LR, Thomas DD
JournalBiophys J
PubMed ID7918987
The Ca-ATPase in the cardiac sarcoplasmic reticulum membrane is regulated by an amphipathic transmembrane protein, phospholamban. We have used time-resolved phosphorescence anisotropy to detect the microsecond rotational dynamics, and thereby the self-association, of the Ca-ATPase as a function of phospholamban phosphorylation and physiologically relevant calcium levels. The phosphorylation of phospholamban ... More
Zinc forms complexes with higher kinetical stability than calcium, 5-F-BAPTA as a good example.
AuthorsCsermely P, Sándor P, Radics L, Somogyi J
JournalBiochem Biophys Res Commun
PubMed ID2512923
Increasing interest is focused on the role of zinc in biological systems. A rapidly growing family of DNA-binding proteins contains "zinc-fingers", where zinc is bound to cysteine or histidine residues. On the other hand zinc is able to displace calcium from its binding sites and in this way it may ... More
Intracellular calcium measurements by 19F NMR of fluorine-labeled chelators.
Symmetrically substituted difluoro derivatives of 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (nFBAPTA) show large 19F NMR chemical shifts on chelating divalent cations. The complexes of Ca2+ with 4FBAPTA and 5FBAPTA show fast and slow exchange behavior, respectively, and the chemical shift or the areas of the resonances from the free and complexed forms can ... More
19F NMR magnetization transfer between 5-FBAPTA and its complexes. An alternative means for measuring free Ca2+ concentration, and detection of complexes with protein in erythrocytes.
AuthorsGilboa H, Chapman BE, Kuchel PW
JournalNMR Biomed
PubMed ID7718434
The 19F NMR Ca(2+)-indicator molecule 5,5'-difluoro-1,2-bis(o- aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (5-FBAPTA) was used in a procedure that enhances its range of applications to measuring free Ca2+ concentrations in buffer solutions and human erythrocytes. Even if the signal from the Ca-5-FBAPTA complex was not visible, the concentration of the complex could be calculated ... More
The effects of proteins on [Ca2+] measurement: different effects on fluorescent and NMR methods.
AuthorsMatsuda S, Kusuoka H, Hashimoto K, Tsujimura E, Nishimura T
JournalCell Calcium
PubMed ID8955557
Previous reports showed that the presence of proteins shifts the apparent dissociation constant (Kd) of a fluorescent dye indicator to Ca2+. To elucidate the sensitivity of Kd of an NMR-sensitive Ca2+ indicator, 5-fluoro-1,2-bis(2-amino-phenoxy)ethane N,N,N'N'-tetraacetic acid (5F-BAPTA) to proteins, and compare with that of a dye indicator, Fura-2, we measured Kd ... More
Nuclear magnetic resonance measurement of cytosolic free calcium levels in human red blood cells.
AuthorsMurphy E, Levy L, Berkowitz LR, Orringer EP, Gabel SA, London RE
JournalAm J Physiol
PubMed ID3094375
Red blood cells were loaded with 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (FBAPTA) by incubation with 50 microM of the acetoxymethyl ester (FBAPTA-AM), and cytosolic free Ca2+ was monitored with 19F-nuclear magnetic resonance (NMR). Loading with 50 microM FBAPTA-AM, which results in a final FBAPTA level of approximately 0.5 mM, caused only a 25-30% ... More
Intracellular free calcium concentration measured with 19F NMR spectroscopy in intact ferret hearts.
AuthorsMarban E, Kitakaze M, Kusuoka H, Porterfield JK, Yue DT, Chacko VP
JournalProc Natl Acad Sci U S A
PubMed ID3112778
Changes in the intracellular free Ca2+ concentration, [Ca2+]i, mediate excitation-contraction coupling in the heart and contribute to cellular injury during ischemia and reperfusion. To study these processes directly, we measured [Ca2+]i in perfused ferret (Mustela putorius furo) hearts using 19F NMR spectroscopy to detect the 5,5'-difluoro derivative of the Ca2+ ... More
Structural and functional characterization of the Zn(II) site in dimethylargininase-1 (DDAH-1) from bovine brain. Zn(II) release activates DDAH-1.
AuthorsKnipp M, Charnock JM, Garner CD, Vasák M
JournalJ Biol Chem
PubMed ID11546769
L-N(omega),N(omega)-dimethylarginine dimethylaminohydrolase-1 (DDAH-1) is a Zn(II)-containing enzyme that, through hydrolysis of side-chain methylated l-arginines, regulates the activity of nitric-oxide synthase. Herein we report the structural and functional properties of the Zn(II)-binding site in DDAH-1 from bovine brain. Activity measurements of the native and metal-free enzyme have revealed that the endogenously ... More
A peroxidative model of human erythrocyte intracellular Ca2+ changes with in vivo cell aging: measurement by 19F-NMR spectroscopy.
AuthorsAiken NR, Galey WR, Satterlee JD
JournalBiochim Biophys Acta
PubMed ID7827135
Numerous changes occur with human erythrocyte aging in vivo, including an increase in free ionic intracellular calcium concentration ([Ca2+]i) (N.R. Aiken et al. (1992) Biochim. Biophys. Acta 1136, 155-160). An attractive hypothesis of cell aging suggests that oxidative stress is responsible for many age-related changes. To determine whether oxidative stress ... More
Neurotoxicity in rats chronically exposed to lead ingestion: measurement of intracellular concentrations of free calcium and lead ions in resting or depolarized brain slices.
AuthorsSingh AK
JournalNeurotoxicology
PubMed ID7603633
The intracellular free calcium (Ca2+) or lead (Pbi2+) ions were measured by using 19F-NMR and 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid in brain slices obtained from control rats and rats chronically exposed to 1 mg/kg.day or 100 mg/kg.day dose of Pb acetate ingestion. The basal Cai2+ values obtained in this study were comparable to ... More
Synthesis and characterization of 19F NMR chelators for measurement of cytosolic free Ca.
AuthorsLevy LA, Murphy E, London RE
JournalAm J Physiol
PubMed ID3105327
Fluorine 19 nuclear magnetic resonance (NMR) studies of intracellular fluorinated calcium chelators provide a useful strategy for the determination of cytosolic free calcium levels in cells and perfused organs. However, the fluorinated chelator with the highest affinity for calcium ions which has been described to date. 1,2-bis-(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (5FBAPTA), exhibits ... More
Lead activation of protein kinase C from rat brain. Determination of free calcium, lead, and zinc by 19F NMR.
AuthorsLong GJ, Rosen JF, Schanne FA
JournalJ Biol Chem
PubMed ID8288636
Lead (Pb2+) has been reported to activate calcium/phospholipid-dependent protein kinase C (PKC) at subnanomolar concentrations (Markovac, J., and Goldstein, G. W. (1988) Nature 334, 732-734); however, others have failed to find any Pb(2+)-induced activation of PKC (Murakami, K., Feng, G., and Chen, S. G. (1993) J. Pharmacol. Exp. Ther. 264, ... More
Pollen tube growth is coupled to the extracellular calcium ion flux and the intracellular calcium gradient: effect of BAPTA-type buffers and hypertonic media.
AuthorsPierson ES, Miller DD, Callaham DA, Shipley AM, Rivers BA, Cresti M, Hepler PK
JournalPlant Cell
PubMed ID7866026
Lily pollen tubes possess a steep, tip-focused intracellular Ca2+ gradient and a tip-directed extracellular Ca2+ influx. Ratiometric ion imaging revealed that the gradient extends from above 3.0 microM at the apex to approximately 0.2 microM within 20 microns from the tip, while application of the Ca(2+)-specific vibrating electrode indicated that ... More
Measurement of cytosolic free calcium in perfused rat heart using TF-BAPTA.
AuthorsMurphy E, Steenbergen C, Levy LA, Gabel S, London RE
JournalAm J Physiol
PubMed ID8203497
The feasibility and usefulness of loading 1,2-bis(2-amino-5,6-difluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (TF-BAPTA), a new high-dissociation constant (KD) (65 microM) Ca2+ indicator, into perfused rat heart is demonstrated. TF-BAPTA-loaded perfused rat heart showed less than a 10% reduction in left ventricular developed pressure. In addition, loading perfused rat heart with TF-BAPTA had no effect ... More
NMR studies of intracellular free calcium, free magnesium and sodium in the guinea pig reticulocyte and mature red cell.
AuthorsJelicks LA, Weaver J, Pollack S, Gupta RK
JournalBiochim Biophys Acta
PubMed ID2474326
During the maturation process reticulocytes lose their intracellular organelles and undergo changes in membrane lipid composition and ion transport properties. While several reports indicate differences in the levels of magnesium, sodium and calcium in reticulocytes and erythrocytes, controversy remains concerning the actual magnitude and direction of ionic alterations during reticulocyte ... More
Glycolytic inhibition and calcium overload as consequences of exogenously generated free radicals in rabbit hearts.
AuthorsCorretti MC, Koretsune Y, Kusuoka H, Chacko VP, Zweier JL, Marban E
JournalJ Clin Invest
PubMed ID1653271
Free radicals have been implicated in the pathogenesis of reperfusion injury, but it is unclear how they exert their deleterious effects on cellular metabolism. Several lines of indirect evidence suggest that free radicals elevate intracellular Ca2+ concentration ([Ca2+]i) and inhibit glycolysis as part of their mechanism of injury. We tested ... More
Multinuclear NMR studies of intracellular cations in the prehypertensive rat kidney.
AuthorsDowd TL, Gupta RK
JournalBiochim Biophys Acta
PubMed ID8155743
We previously reported a significant derangement of intracellular free calcium ion concentration in the isolated perfused kidney of adult spontaneously hypertensive rat (SHR) (J. Biol. Chem. 267, 3637-3643, 1992). In order to investigate whether an abnormality in intracellular free calcium or another ion precedes the development of elevated blood pressure ... More
Ca(2+)-dependent changes in the mitochondrial energetics in single dissociated mouse sensory neurons.
AuthorsDuchen MR
JournalBiochem J
PubMed ID1373604
Depolarization of neurons promotes Ca2+ influx through voltage-activated channels, raising the intracellular Ca2+ concentration ([Ca2+]i). The consequences of such changes in [Ca2+]i for mitochondrial function were assessed in single, freshly dissociated mammalian neurons. Microfluorimetric techniques were used to measure [Ca2+]i, mitochondrial membrane potential [delta psi m, Rhodamine 123 (Rh 123) ... More
AuthorsMcHugh D, Flemming R, Xu SZ, Perraud AL, Beech DJ
JournalJ Biol Chem
PubMed ID12529379
TRPM2 is a member of the melastatin-related TRP (transient receptor potential) subfamily. It is expressed in brain and lymphocytes and forms a cation channel that is activated by intracellular ADP-ribose and associated with cell death. In this study we investigated the calcium dependence of human TRPM2 expressed under a tetracycline-dependent ... More
NMR measurement of cytosolic free calcium, free magnesium, and intracellular sodium in the aorta of the normal and spontaneously hypertensive rat.
AuthorsJelicks LA, Gupta RK
JournalJ Biol Chem
PubMed ID2295635
We have utilized multinuclear NMR spectroscopy to examine the relationship between cytosolic free Ca2+ ([Ca2+]in), free Mg2+ ([Mg2+]in) and intracellular Na+ ([Na+]in) levels of the intact thoracic aorta and primary hypertension using the Wistar-Kyoto and Sprague-Dawley rats as controls and the spontaneously hypertensive rat as a model for genetic hypertension. ... More
Calcium buffer injections delay cleavage in Xenopus laevis blastomeres.
AuthorsSnow P, Nuccitelli R
JournalJ Cell Biol
PubMed ID8320261
Microinjection of calcium buffers into the two-cell Xenopus laevis embryo delays cell division in a dose-dependent manner. Four calcium buffers in the BAPTA series with different affinities for calcium were used to distinguish between a localized calcium gradient regulating cleavage and the global calcium concentration regulating this event. DibromoBAPTA (Kd ... More
Cytosolic free calcium levels in sickle red blood cells.
AuthorsMurphy E, Berkowitz LR, Orringer E, Levy L, Gabel SA, London RE
JournalBlood
PubMed ID3105623
In this study, we used a recently developed nuclear magnetic resonance (NMR) technique to measure ionized calcium in sickle erythrocytes. The NMR technique, which involves 19F NMR studies of a fluorinated calcium chelator quinMF, [2-(2-amino-4-methyl-5-fluorophenoxy)methyl-8-aminoquinoline-N,N,N',N'- tetraacetic acid] provides a novel approach to the study of ionized calcium in erythrocytes since ... More
New calcium-sensitive ligand for nuclear magnetic resonance spectroscopy.
AuthorsRobitaille PM, Jiang Z
JournalBiochemistry
PubMed ID1472494
Fluorinated calcium-sensitive indicators such as 5,5'-difluoro-1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (difluoro-BAPTA) will often be less sensitive under in vivo conditions than gyromagnetic ratio considerations alone would have predicted. This is due to the very broad line widths displayed by these molecules within the living cell. In order to provide a spectroscopic alternative to ... More
Measurement of cytosolic free magnesium ion concentration by 19F NMR.
AuthorsLevy LA, Murphy E, Raju B, London RE
JournalBiochemistry
PubMed ID3415971
Fluorinated derivatives of the chelator o-aminophenol-N,N,O-triacetic acid (APTRA) have been developed, synthesized, and analyzed for use as 19F NMR indicators of free cytosolic magnesium concentration. Magnesium dissociation constants for the 4-fluoro, 5-fluoro, and 4-methyl-5-fluoro species were determined to be 3.1, 0.9, and 0.6 mM, respectively, on the basis of UV ... More