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Failla ML, Chitchumronchokchai C, Ferruzzi MG, Goltz SR, Campbell WW. Unsaturated fatty acids promote bioaccessibility and basolateral secretion of carotenoids and α-tocopherol by Caco-2 cells. Food Funct 2014; 5:1101-12. [PMID: 24710065 DOI: 10.1039/c3fo60599j] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Bioavailability of carotenoids and tocopherols from foods is determined by the efficiency of transfer from food/meal to mixed micelles during digestion, incorporation into chylomicrons for trans-epithelial transport to lymphatic/blood system, and distribution to target tissues.
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Affiliation(s)
- Mark L. Failla
- Department of Human Sciences
- Human Nutrition Program
- The Ohio State University
- Columbus, USA
| | | | - Mario G. Ferruzzi
- Department of Food Science
- Purdue University
- West Lafayette, USA
- Department of Nutrition Science
- Purdue University
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2
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Glynn IM, Karlish SJ. Different approaches to the mechanism of the sodium pump. CIBA FOUNDATION SYMPOSIUM 2008:205-23. [PMID: 125188 DOI: 10.1002/9780470720134.ch12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The way in which the sodium pump uses energy from the hydrolysis of ATP to perform osmotic and electrical work is not yet understood. We attempt to bring together the results of a number of different approaches to this problem. One approach has been to correlate biochemical changes and ionic fluxes, both when the pump operates normally and when it operates in various abnormal 'modes' in particular unphysiological conditions. A second approach has been to expose fragments of cell membrane to (gamma-32P)ATP and to study the properties of components of the membrane that become labelled. It is now clear that 32P can be transferred to the beta-carboxy group of an aspartyl residue in a pump polypeptide, but there is controversy about the interrelations of different forms of this polypeptide and its role, if any, in the normal functioning of the pump. A third approach has been to attempt to purify the pump and to determine the properties of the pure enzyme. It seems that the pump contains a polypeptide (molecular weight about 100,000), which bears the phosphorylation site, and a smaller glycopeptide, but there is disagreement about the molecular ratios. The results of these and other approaches cannot yet be fitted into a satisfactory model for the sodium pump, but we shall consider some of the problems involved in this task.
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3
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Ward DG, Cavieres JD. Photoinactivation of fluorescein isothiocyanate-modified Na,K-ATPase by 2'(3')-O-(2,4,6-trinitrophenyl)8-azidoadenosine 5'-diphosphate. Abolition of E1 and E2 partial reactions by sequential block of high and low affinity nucleotide sites. J Biol Chem 1998; 273:14277-84. [PMID: 9603934 DOI: 10.1074/jbc.273.23.14277] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Na,K-ATPase activity of the sodium pump exhibits apparent multisite kinetics toward ATP, a feature that is inherent to the minimal enzyme unit, the alpha beta protomer. We have argued that this should arise from separate catalytic and noncatalytic sites on the alpha beta protomer as fluorescein isothiocyanate (FITC) blocks a high affinity ATP site on all alpha subunits and yet the modified Na, K-ATPase retains a low affinity response to nucleotides (Ward, D. G., and Cavieres, J. D. (1996) J. Biol. Chem. 271, 12317-12321). We now find that 2'(3')-O-(2,4,6-trinitrophenyl)8-azido-adenosine 5'-diphosphate (TNP-8N3-ADP), a high affinity photoactivatable analogue of ATP, can inhibit the K+-phosphatase activity of the FITC-modified enzyme during assays in dimmed light. The inhibition occurs with a Ki of 140 microM at 20 mM K+; it requires the adenine ring as 2'(3')-O-(2,4 6-trinitrophenyl) (TNP)-UDP or TNP-uridine are less potent and 2,4,6-trinitrobenzene-sulfonate is ineffective. Under irradiation with UV light, TNP-8N3-ADP inactivates the K+-phosphatase activity of the fluorescein-enzyme and also its phosphorylation by [32P]Pi. The photoinactivation process is stimulated by Na+ or Mg2+, and is inhibited by K+ or excess TNP-ADP. In the presence of 50 mM Na+ and 1 mM Mg2+, TNP-8N3-ADP photoinactivates with a K0.5 of 15 microM. Furthermore, TNP-8N3-ADP photoinactivates the FITC-modified, solubilized alpha beta protomers, even more effectively than the membrane-bound fluorescein-enzyme. These results strongly suggest that catalytic and allosteric ATP sites coexist on the alpha beta protomer of Na,K-ATPase.
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Affiliation(s)
- D G Ward
- Transport ATPase Laboratory, Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, LE1 9HN, United Kingdom
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4
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Waheed AA, Gupta PD. Changes in structural and functional properties of rat intestinal brush border membrane during starvation. Life Sci 1998; 61:2425-33. [PMID: 9416761 DOI: 10.1016/s0024-3205(97)00977-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Changes in surface area of microvilli, fluidity of brush border membrane and transport of L-amino acids through intestinal epithelial cells were studied in wellfed and starved (2,4 and 6 days) rats. The surface area of microvilli per unit area of intestinal epithelial cells increased during starvation. Studies with fluoroprobes - pyrene, 1-anilinonaphthalene-8-sulphonate and 1,6-diphenyl-1,3,5-hexatriene, showed increased fluidity of brush border membrane on progressive starvation. Transport of five amino acids representing five different transport systems was studied during starvation in everted intestinal sleeves. Transport of L-proline, glycine and L-glutamic acid which represent imino, glycine and acidic systems respectively increased significantly in Na+-dependent pathway whereas transport of L-lysine representing basic system increased significantly in Na+-independent pathway during starvation.
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Affiliation(s)
- A A Waheed
- Centre for Cellular and Molecular Biology, Hyderabad, India
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5
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Suvitayavat W, Dunham PB, Haas M, Rao MC. Characterization of the proteins of the intestinal Na(+)-K(+)-2Cl- cotransporter. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 267:C375-84. [PMID: 8074174 DOI: 10.1152/ajpcell.1994.267.2.c375] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Absorptive intestinal epithelia, such as that of the winter flounder, absorb salt via a bumetanide-sensitive Na(+)-K(+)-2Cl- cotransport mechanism on the brush-border membrane (BBM). The present study demonstrates the first molecular characterization of the intestinal Na(+)-K(+)-2Cl- cotransporter and its unique regulation. The photoaffinity bumetanide analogue, 4-[3H]benzoyl-5-sulfamoyl-3- (3-thenyloxy)benzoic acid, specifically labeled three groups of proteins in flounder intestinal microsomal membranes (MM): a approximately 180-kDa peptide, prominently labeled, and diffuse bands at approximately 110-70 and 50 kDa, less intensely labeled. Subcellular fractionation revealed a single prominently labeled protein of approximately 170 kDa in BBM but not in basolateral membranes (BLM) and little or no labeling of proteins of approximately 110-70 or 50 kDa. Polyclonal antiserum raised against the Ehrlich ascites cell cotransporter identified a 180-kDa peptide in MM and a 175-kDa peptide (pI approximately 5.4) in BBM but none in BLM or in the cytosol of flounder intestine. As predicted from the regulation of cotransport in this tissue, phosphorylation of this protein is increased by guanosine 3',5'-cyclic monophosphate (cGMP)-dependent but not by adenosine 3',5'-cyclic monophosphate-dependent protein kinase. In addition, phosphorylation of the protein is not increased by protein kinase C or Ca2+/calmodulin-dependent protein kinase but is increased by the phosphatase inhibitor calyculin A. Finally, calyculin A preserves the inhibitory effect of cGMP on ion transport, even in the absence of the nucleotide, suggesting that phosphorylation-dephosphorylation mechanisms are crucial in cotransporter regulation. Thus the flounder intestinal cotransporter is a approximately 175-kDa BBM protein that can be regulated by phosphorylation.
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Affiliation(s)
- W Suvitayavat
- Department of Physiology and Biophysics, University of Illinois at Chicago 60612
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6
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Repke KR, Schön R. Chemistry and energetics of transphosphorylations in the mechanism of Na+/K(+)-transporting ATPase: an attempt at a unifying model. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1154:1-16. [PMID: 8389589 DOI: 10.1016/0304-4157(93)90014-f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- K R Repke
- Energy Conversion Unit, Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
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7
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Robinson JD, Pratap PR. Indicators of conformational changes in the Na+/K(+)-ATPase and their interpretation. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1154:83-104. [PMID: 8389590 DOI: 10.1016/0304-4157(93)90018-j] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- J D Robinson
- Department of Pharmacology State University of New York Health Science Center, Syracuse 13210
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Rajanna B, Chetty CS, Rajanna S. Effect of mercuric chloride on the kinetics of cationic and substrate activation of the rat brain microsomal ATPase system. Biochem Pharmacol 1990; 39:1935-40. [PMID: 2162172 DOI: 10.1016/0006-2952(90)90612-o] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mercuric chloride (HgCl2), a neurotoxic compound, inhibited the adenosine triphosphatase (ATPase) system in a concentration-dependent manner. Hydrolysis of ATP was linear with time with or without HgCl2 in the reaction mixtures. Higher inhibition of (Na(+)-K+)ATPase activity by HgCl2 was observed in alkaline (8.0 to 9.0) pH and at lower temperatures (17 to 32 degrees). Activation energy values were increased slightly in the presence of HgCl2. Activation of (Na(+)-K+)ATPase by ATP in the presence of HgCl2 showed a decrease in Vmax from 15.29 to 5.0 mumol of inorganic phosphate (Pi)/mg protein/hr with no change in Km. Similarly, activation of K(+)-stimulated p-nitrophenyl phosphatase (K(+)-PNPPase) in the presence of HgCl2 showed a decrease in Vmax from 3.26 to 1.35 mumols of p-nitrophenol (PNP)/mg protein/hr with no change in Km. K(+)-activation kinetic studies indicated that HgCl2 decreased Vmax from 14.01 to 4.30 mumols Pi/mg protein/hr in the case of (Na(+)-K+)ATPase and from 3.45 to 2.40 mumols PNP/mg protein/hr in the case of K(+)-PNPPase with no changes in Km. Na(+)-activation of (Na(+)-K+)ATPase in the presence of HgCl2 showed a decrease in Vmax from 11.06 to 3.23 mumols Pi/mg protein/hr and an increase in Km from 1.06 to 2.08 mM. Preincubation of microsomes with sulfhydryl (SH) agents dithiothreitol, cysteine and glutathione protected HgCl2-inhibition of (Na(+)-K+)ATPase. The data suggest that HgCl2 inhibited (Na(+)-K+)ATPase by interfering with the dephosphorylation of the enzyme-phosphoryl complex.
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Affiliation(s)
- B Rajanna
- Department of Natural Science, Selma University, AL 36701
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9
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Brasitus TA, Dahiya R, Dudeja PK. Rat proximal small intestinal Golgi membranes: lipid composition and fluidity. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 958:218-26. [PMID: 3337837 DOI: 10.1016/0005-2760(88)90180-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The present studies were conducted to examine and characterize the lipid composition and physical state of the membrane lipids of rat proximal small intestinal Golgi membranes. Golgi membranes were purified from isolated enterocytes; lipids were extracted from these membranes and analyzed by thin-layer and gas-liquid chromatography. The 'static' and 'dynamic' components of fluidity of Golgi membranes and their liposomes were assessed by steady-state fluorescence polarization techniques utilizing r infinity and S values of 1,6-diphenyl-1,3,5-hexatriene and r values of DL-2-(9-anthroyl)- and DL-12-(9-anthroyl)stearic acid, respectively. Additional studies were also performed on these membranes, using benzyl and methyl alcohol, to examine the relationship between alterations in lipid fluidity and glycosphingolipid glycosyltransferase activities. The results of these studies demonstrated that: (1) the principal phospholipids and neutral lipids of intestinal Golgi membranes, respectively, were phosphatidylcholine, phosphatidylethanolamine and sphingomyelin, and unesterified cholesterol and fatty acids; (2) the major fatty acids of Golgi membranes were palmitic (16:0), stearic (18:0), linoleic (18:2), arachidonic (20:4) and oleic (18:1) acids; (3) fluorescence polarization studies using diphenylhexatriene detected a thermotropic transition at 24-26 degrees C in Golgi membranes and liposomes prepared from lipid extracts of these membranes; (4) benzyl alcohol (25 and 50 mM) but not methyl alcohol (50 mM) significantly increased the fluidity of these membranes; and (5) at these same concentrations, benzyl alcohol was also found to increase significantly the specific activity of UDP-galactosyllactosylceramide galactosyltransferase but not CMP-acetylneuraminic acid: lactosylceramide sialyltransferase. Methyl alcohol was not found to influence either enzyme's activity in these membranes.
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Affiliation(s)
- T A Brasitus
- Department of Medicine, University of Chicago Hospitals and Clinics, IL 60637
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10
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Ahammadsahib KI, Ramamurthi R, Dusaiah D. Mechanism of inhibition of rat brain (Na+-K+)-stimulated adenosine triphosphatase reaction by cadmium and methyl mercury. JOURNAL OF BIOCHEMICAL TOXICOLOGY 1987; 2:169-80. [PMID: 2854566 DOI: 10.1002/jbt.2570020303] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The mechanisms of inhibition of rat brain Na+-K+-ATPase by cadmium chloride (CdCl2) and methylmercuric chloride (CH3HgCl) were studied in vitro by assessing the effects of these heavy metals on this enzyme and associated component parameters. Both the heavy metals significantly inhibited the overall Na+-K+-ATPase in a concentration-dependent manner with an estimated median inhibitory concentration (IC-50) of 3.2 X 10(-5) M for CdCl2 and 6 X 10(-6) M for CH3HgCl. Protection of enzyme against heavy metal inhibition by 5 X 10(-5) M to 1 X 10(-4) M dithiothreitol (DTT) and glutathione (GSH) or cysteine (CST) indicates that both monothiols and dithiols have the same ability in regenerating sulfhydryl (-SH) groups or chelating the metals. Inhibition of K+-p-nitrophenyl phosphatase (K+-PNPPase), the component enzyme catalyzing the K+-dependent dephosphorylation in the overall Na+-K+-ATPase reaction by these heavy metals, indicates that the mechanism of inhibition involves binding to this phosphatase. Reversal of K+-PNPPase inhibition by DTT, GSH, and CST suggests sulfhydryl groups as binding sites. Binding of 3H-ouabain, a cardiac glycocide and inhibitor of both phosphorylation and dephosphorylation, to brain fraction was significantly decreased by CH3HgCl, and this inhibition was reversed by the three thiol compounds, suggesting presence of -SH group(s) in the ouabain receptor site. Cadmium chloride failed to inhibit the binding of this receptor, indicating that the mechanics of inhibition of ATPase by CH3HgCl and CdCl2 are different from each other. The results suggest that the critical conformational property of enzyme common to both kinase (E1) and phosphatase (E2) is susceptible to CH3HgCl whereas only phosphatase is sensitive to CdCl2.
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Affiliation(s)
- K I Ahammadsahib
- Department of Neurology, University of Mississippi Medical Center, Jackson 39216
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11
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Fu YF, Schuurmans Stekhoven FM, Swarts HG, de Pont JJ, Bonting SL. The locus of nucleotide specificity in the reaction mechanism of (Na+ + K+)-ATPase determined with ATP and GTP as substrates. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 817:7-16. [PMID: 2988622 DOI: 10.1016/0005-2736(85)90062-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
ATP and GTP have been compared as substrates for (Na+ + K+)-ATPase in Na+-activated hydrolysis, Na+-activated phosphorylation, and the E2K----E1K transition. Without added K+ the optimal Na+-activated hydrolysis rates in imidazole-HCl (pH 7.2) are equal, but are reached at different Na+ concentrations: 80 mM Na+ for GTP, 300 mM Na+ for ATP. The affinities of the substrates for the enzyme are widely different: Km for ATP 0.6 microM, for GTP 147 microM. The Mg-complexed nucleotides antagonize activation as well as inhibition by Na+, depending on the affinity and concentration of the substrate. The optimal 3-s phosphorylation levels in imidazole-HCl (pH 7.0) are equally high for the two substrates (3.6 nmol/mg protein). The Km value for ATP is 0.1-0.2 microM and for GTP it ranges from 50 to 170 microM, depending on the Na+ concentration. The affinity of Na+ for the enzyme in phosphorylation is lower with the lower affinity substrate: Km (Na+) is 1.1 mM with ATP and 3.6 mM with GTP. The GTP-phosphorylated intermediate exists, like the ATP-phosphorylated intermediate, in the E2P conformation. Addition of K+ increases the optimal hydrolytic activity 30-fold for ATP (at 100 mM Na+ + 10 mM K+) and 2-fold for GTP (at 100 mM Na+ + 0.16 mM K+). K+ greatly increases the Km values for both substrates (to 430 microM for ATP and 320 microM for GTP). Above 0.16 mM K+ inhibits GTP hydrolysis. GTP does not reverse the quenching effect of K+ on the fluorescence of the 5-iodoacetamidofluorescein-labeled enzyme. ATP fully reverses this effect, which represents the transition from E1K to E2K. Hence GTP is unable to drive the E2K----E1K transition.
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12
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Rubinoff MJ, Nellans HN. Active calcium sequestration by intestinal microsomes. Stimulation by increased calcium load. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)39526-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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13
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Brasitus TA, Keresztes RS. Protein-lipid interactions in antipodal plasma membranes of rat colonocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 773:290-300. [PMID: 6329287 DOI: 10.1016/0005-2736(84)90093-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The isolation of apical membranes from rat proximal colonic epithelial cells is described. Differential centrifugation yielded a 'crude' membrane fraction which was further purified using sucrose density centrifugation. The final membrane fraction was enriched 20-28-fold over homogenate in alkaline phosphatase and cysteine-sensitive alkaline phosphatase specific activities. Lipid-protein interactions and lipid dynamics examined in apical and basolateral membranes prepared from colonocytes demonstrated: (1) apical membrane, as assessed by steady-state fluorescence polarization studies have a low lipid fluidity; (2) colonic basolateral membranes possess a greater lipid fluidity than apical membranes; (3) compositional differences in these antipodal membranes appear to explain these differences in lipid fluidity; (4) fluorescence polarization studies using diphenylhexatriene detect a thermotropic transition at 21-23 degrees C in apical membranes and liposomes prepared from lipid extracts of these membranes; (5) alkaline phosphatase and L-cysteine-sensitive alkaline phosphatase activities appear to be functionally dependent on the physical state of the apical membrane's lipid.
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Abstract
Specific binding sites for vasopressin (AVP) were located in subcellular particulate fractions of rat brain with tritiated vasopressin of high specific activity, 22.5 Ci/mmol. Rat brain tissue was dissected, placed in cold 0.32 M sucrose containing proteolytic inhibitors, homogenized and fractionated into a crude nuclear fraction (1K pellet), crude mitochondrial fractions (12K pellet), and plasma membranes and microsomes (100K pellet). Specific binding of vasopressin was found in the 12K and 100K pellets in the presence of a divalent metal ion with Ni greater than Co greater than Mg greater than Mn greater than no metal ion at pH 7.4 in 50 mM Tris-Maleate buffer. Maximum specific binding of 16 nM AVP was located in the 100K anterior cortex fraction which bound 350 fmoles/mg protein; striatum, midbrain/thalamus, cerebellum, and medulla oblongata and pons bound specifically about 200 fmoles/mg protein and frontal poles and parietal cortex about 100 fmoles/mg protein in the 100K pellet. In all of the brain regions studied, except hippocampus and septum, the 100K pellet bound specifically 2 to 4 times more 3H-AVP than the 12K pellet. In the hippocampus with 16 nM AVP, the 12K pellet bound specifically 150 fmoles/mg protein; the septum, 75 fmoles/mg protein. Little or no binding to the 100K pellet was present in these regions. Bound AVP could be dissociated rapidly from the membranes by the addition of EDTA. The 12K hippocampal pellet was further fractionated into myelin, mitochondria, and synaptosomes; purification was confirmed by marker enzyme assays.(ABSTRACT TRUNCATED AT 250 WORDS)
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Brasitus TA, Keresztes RS. Isolation and partial characterization of basolateral membranes from rat proximal colonic epithelial cells. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 728:11-9. [PMID: 6830771 DOI: 10.1016/0005-2736(83)90431-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The isolation of basolateral membranes from rat proximal colonic epithelial cells is described. Cells were harvested using a technique combining chelation of divalent cations with mechanical dissociation. After homogenization, differential centrifugation yielded a 'crude' membrane fraction which was further purified using sucrose density centrifugation. The final membrane fraction was enriched 10-14-fold over homogenate in ouabain-sensitive sodium-potassium dependent adenosine triphosphatase and ouabain-sensitive potassium-dependent phosphatase specific activities. SDS-polyacrylamide gel electrophoresis of this membrane revealed at least 18 protein bands with molecular weights of 14600-200000. Phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, free cholesterol and fatty acids were the major lipid components of this membrane. The predominant fatty acids were palmitic (16:0), oleic (18:1), stearic (18:0) and linoleic (18:2) acid. Membranes and their liposomes were studied, using the lipid soluble fluorophore 1,6-diphenyl-1,3,5-hexatriene (DPH), by steady-state fluorescence polarization. The fluorescence anisotropy was greater in the intact membranes compared to their liposomes, indicating greater fluidity in the liposomes. Compositional studies suggested that the high fluidity of this membrane was due to its low ratios of protein/lipid (w/w), cholesterol/phospholipid (mol/mol), and sphingomyelin/phosphatidylcholine (mol/mol).
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16
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Patzelt-Wenczler R, Mertens W. Effects of cations on high-affinity and low-affinity ATP-binding sites of (Na+, K+)-ATPase as studied by disulfides of thioinosine triphosphate and its analogue. EUROPEAN JOURNAL OF BIOCHEMISTRY 1981; 121:197-202. [PMID: 6276169 DOI: 10.1111/j.1432-1033.1981.tb06449.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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17
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Nellans H, Popovitch J. Calmodulin-regulated, ATP-driven calcium transport by basolateral membranes of rat small intestine. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68719-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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18
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Brasitus TA, Schachter D. Membrane lipids can modulate guanylate cyclase activity of rat intestinal microvillus membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 630:152-6. [PMID: 6104514 DOI: 10.1016/0304-4165(80)90147-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Studies of the temperature dependence (10-40 degrees C) of guanylate cyclase in rat intestinal microbillus membranes reveal a change in energy of activation (slope of the Arrhenius plot) at 30 +/- 1 degree C. The break point temperature corresponds to the lipid thermotropic transition in these membranes previously characterized by differential scanning calorimetry (range: 23-39 degrees C; peak temperature, 31 degrees C). The break point temperature for guanylate cyclase also corresponds to that of a number of other microbillus membrane enzymes and of D-glucose transport. These activities are defined as "intrinsic" membrane activities by this operational criterion. Treatment with the nonionic detergent Lubrol WX increased the guanylate cyclase activity 4- to 8-fold and removed the discontinuity in the Arrhenius plot.
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19
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Siegel G, Iyengar S, Fogt S. Electrophorus electricus (Na+ + K+)-ATPase. Evidence for simultaneous Na+ and K+ binding in the presence of Pb2+. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)85616-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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20
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Brasitus TA, Tall AR, Schachter D. Thermotropic transitions in rat intestinal plasma membranes studied by differential scanning calorimetry and fluorescence polarization. Biochemistry 1980; 19:1256-61. [PMID: 7370232 DOI: 10.1021/bi00547a033] [Citation(s) in RCA: 113] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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21
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Gettelfinger DM, Siegel GJ. Irreversible zinc ion inhibition of (Na+ -K+)-adenosinetriphosphatase, Na+ -phosphorylation, and K+-p-nitrophenylphosphatase of Electrophorus electricus electroplax. J Neurochem 1978; 31:1231-7. [PMID: 212536 DOI: 10.1111/j.1471-4159.1978.tb06247.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Siegel G, Fogt S, Iyengar S. Characteristics of lead ion-stimulated phosphorylation of Electrophorus electricus electroplax (Na+ + K+)-adenosine triphosphatase and inhibition of ATP-ADP exchange. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34485-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Rimon G. Substrate inhibition of the (Na+, K+)-ATPase in the presence of excess Mg2+. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 485:434-45. [PMID: 144534 DOI: 10.1016/0005-2744(77)90179-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. High concentrations of ATP inhibit completely the activity of (Na+, K+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) prepared from sheep brain. 2. The inhibition depends on the concentration of total ATP, i.e. complexed ATP+ free ATP. 3. The inhibition by high ATP concentrations persists in the absence of K+, and is then independent of the Na+ concentration between 2 and 140 mM Na+. 4. Raising the K+ concentration at 20 mM Na+ increases the ATP concentration required for the maximal hydrolysis rate. 5. The Hill number for the inhibition process is about three. 6. The inhibition by ATP is temperature-dependent, in that as the temperature is increased, higher ATP concentrations are required for inhibition.
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Wang T, Lindenmayer GE, Schwartz A. Steady-state kinetic study of magnesium and ATP effects on ligand affinity and catalytic activity of sheep kidney sodium, potassium-adenosinetriphosphatase. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 484:140-60. [PMID: 142515 DOI: 10.1016/0005-2744(77)90120-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Henderson GR, Askari A. Transport ATPase: further studies on the properties of the thimerosal-treated enzyme. Arch Biochem Biophys 1977; 182:221-6. [PMID: 142444 DOI: 10.1016/0003-9861(77)90302-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Siegel GJ, Fogt SK, Hurley MJ. Lead actions on sodium-plus-potassium-activated adenosinetriphosphatase from electroplax, rat brain, and rat kidney. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1977; 84:465-93. [PMID: 197830 DOI: 10.1007/978-1-4684-3279-4_21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Inorganic lead ion, in micromolar concentrations, reversibly inhibits the sodium-plus-potassium-activated adenosinetriphosphatase (ATPase) and potassium-activated p-nitrophenylphosphatase (NPPase) activities of microsomal fractions from electric organ, rat kidney, and rat brain. In the presence of 3 mM MgC12 and 3 mM ATP, the concentrations of PbC12 producing half-maximal inhibition of the ATPase from these tissues are 4 X 10(-6) M, 20 X 10(-6) M, and 55 X 10(-6) M, respectively. The corresponding values for inhibition of the NPPase are 10(-6) M, 53 X 10(-6) M, and 22 X 10(-6) M. PbC12 also stimulates the phosphorylation by [gamma-32P]ATP of a microsomal protein from all three tissues in the absence of added sodium ion. This reaction was extensively studied with electroplax microsomes. In common with the well-known Na+-dependent phosphorylation of (Na+ + K+)-ATPase, the Pb2 -dependent reaction is inhibited by ouabain, specific for ATP, dependent on Mg2+, and yields and acid-stable phosphoprotein with a molecular weight of 98,000 in sodium dodecylsulfate. The Pb2+-dependent phosphoprotein, however, is not sensitive to K+. These observations are pertinent to the biochemistry and toxicity of inorganic lead in tissues and to the molecular mechanism of the cation transport enzyme.
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Siegel GJ, Fogt SK. Lead ion activates phosphorylation of electroplax Na+- and K+-dependent adenosine triphosphatase ((NaK)-ATPase) in the absence of sodium ion. Arch Biochem Biophys 1976; 174:744-6. [PMID: 132899 DOI: 10.1016/0003-9861(76)90405-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Henderson GR, Askari A. Transport ATPase: thimerosal inhibits the Na+ +K+-dependent ATPase activity without diminishing the Na+-dependent ATPase activity. Biochem Biophys Res Commun 1976; 69:499-505. [PMID: 131551 DOI: 10.1016/0006-291x(76)90549-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Goldman SS, Albers RW. Cold resistance of the brain during hibernation. Temperature sensitivity of the partial reactions of the Na+, K+-ATPase. Arch Biochem Biophys 1975; 169:540-4. [PMID: 170866 DOI: 10.1016/0003-9861(75)90197-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Na+ATPase of the mammalian erythrocyte membrane. Reversibility of phosphorylation at 0 degrees. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41167-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Whittam R, Chipperfield AR. The reaction mechanism of the sodium pump. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 415:149-71. [PMID: 238660 DOI: 10.1016/0304-4157(75)90001-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Tobin T, Akera T, Brody TM. Gel electrophoretic identity of the (Na+ + Mg-2+)- and (Na+ + Ca-2+)-stimulated phosphorylations of rat brain ATPase. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 389:117-25. [PMID: 124586 DOI: 10.1016/0005-2736(75)90389-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The classical E2-P intermediate of (Na+ + K+)-ATPase dephosphorylates readily in the presence of K+ and is not affected by the addition of ADP. To determine the significance in the reaction cycle of (Na+ + K+)-ATPase of kinetically atypical phosphorylations of rat brain (Na+ + K+)-ATPase we compared these phosphorylated components with the classical E2-P intermediate of this enzyme by gel electrophoresis. When rat brain (Na+ + K+)-ATPase was phosphorylated in the presence of high concentrations of Na+ a proportion of the phosphorylated material formed was sensitive to ADP but resistant to K+. Similarly, if phosphorylation was carried out in the presence of Na+ and Ca-2+ up to 300 pmol/mg protein of a K+ -resistant, ADP-sensitive material were formed. If phosphorylation was from [gamma-32-P]CTP up to 800 pmol-32-P/mg protein of an ADP-resistant, K+ -sensitive phosphorylated material were formed. On gel electrophoresis these phosphorylated materials co-migrated with authentic Na+ -stimulated, K+ -sensitive, E2-P-phosphorylated intermediate of (Na+ + K+)-ATPase, supporting suggestions that they represent phosphorylated intermediates in the reaction sequence of this enzyme.
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Swann AC, Albers W. Sodium + potassium-activated ATPase of mammalian brain. Regulation of phosphatase activity. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 382:437-56. [PMID: 164910 DOI: 10.1016/0005-2736(75)90283-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. The K+-nitrophenylphosphatase activity associated with mammalian brain (Na+ + K+)-ATPase displays K+ activation curves that have intermediary plateaus and maxima in the presence of less than saturating concentrations of Na+. Zero Na+ and saturating Na+ produce sigmoid K+-activation curves with low and high K+ affinities respectively. 2. ATP inhibits K+-activated nitrophenylphosphatase through both competitive and non-competitive mechanisms. ATP is synergistic with Na+ in the mechanism which converts the enzyme from low to high K+ affinity. 3. The Na+ and K+ interactions can be accounted for by equations which describe a model with separate regulatory sites for Na+ and K+ and with K+- requiring catalytic site which is only accessible in one of the two principal conformational stages of the enzyme. 4. The effects of ATP can be accounted for by the same model through interactions at a single nucleotide binding site. Inhibition which is competitive with K+ and non-competitive with substrate arises from stabilization of the inactive enzyme conformation. Inhibition which is non-competitive with K+ and competitive with substrate results from interactions with the active enzyme conformation. The synergism between Na+ and ATP appears to arise as a consequence of the formation of phosphoryl enzyme. 5. A model for (Na+ + K+)-ATPase is discussed which involves in-phase coupling of subunit interactions as suggested by these studies.
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Maheshwari UR, Chan SL, Trevor AJ. Reversible inhibition of mammalian brain acetylcholinesterase and sodium potassium-stimulated adenosine triphosphatase by cyclopropane. Biochem Pharmacol 1975; 24:663-9. [PMID: 123745 DOI: 10.1016/0006-2952(75)90241-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Albers RW, Koval GJ, Swann AC. Analysis of Na+, K+ and nucleotide interactions in terms of a heterotropic relaxation model for (Na+-K+)-ATPase. Ann N Y Acad Sci 1974; 242:268-79. [PMID: 4372924 DOI: 10.1111/j.1749-6632.1974.tb19096.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Banerjee SP. Participation of cytidine triphosphate in sodium-dependent phosphorylation, transphosphorylation, and hydrolysis: evidence for two hydrolytic sites in sodium ion-plus potassium ion-dependent adenosine triphosphatase. Ann N Y Acad Sci 1974; 242:139-48. [PMID: 4279584 DOI: 10.1111/j.1749-6632.1974.tb19086.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Siegel GJ, Goodwin BB, Hurley MJ. Regulatory effects of potassium on (Na+ plus K+)-activated adenosinetriphosphatase. Ann N Y Acad Sci 1974; 242:220-34. [PMID: 4279589 DOI: 10.1111/j.1749-6632.1974.tb19092.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Blostein R, Whittington ES, Kuebler ES. Na+-ATPase of mammalian erythrocyte membranes: kinetic changes associated with postnatal development and following active erythropoiesis. Ann N Y Acad Sci 1974; 242:305-16. [PMID: 4279593 DOI: 10.1111/j.1749-6632.1974.tb19099.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Yoda A. Association and dissociation rate constants of the complexes between various cardiac monoglycosides and Na, K-ATPase. Ann N Y Acad Sci 1974; 242:598-616. [PMID: 4279608 DOI: 10.1111/j.1749-6632.1974.tb19120.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Karlish SJ, Glynn IM. An uncoupled efflux of sodium ions from human red cells, probably associated with Na-dependent ATPase activity. Ann N Y Acad Sci 1974; 242:461-70. [PMID: 4279599 DOI: 10.1111/j.1749-6632.1974.tb19110.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tonomura Y, Fukushima Y. Kinetic properties of phosphorylated intermediates in the reaction of Na+, K+-ATPase. Ann N Y Acad Sci 1974; 242:92-105. [PMID: 4530700 DOI: 10.1111/j.1749-6632.1974.tb19082.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Inagaki C, Lindenmayer GE, Schwartz A. Effects of Sodium and Potassium on Binding of Ouabain to the Transport Adenosine Triphosphatase. J Biol Chem 1974. [DOI: 10.1016/s0021-9258(19)42338-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Wallick ET, Schwartz A. Thermodynamics of the Rate of Binding of Ouabain to the Sodium, Potassium-Adenosine Triphosphatase. J Biol Chem 1974. [DOI: 10.1016/s0021-9258(19)42339-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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45
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Kaniike K, Erdmann E, Schoner W. Study on the differential modifications of (Na+ plus K+)-ATPase and its partial reactions by dimethylsulfoxide. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 352:275-86. [PMID: 4276212 DOI: 10.1016/0005-2736(74)90219-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tobin T, Akera T, Lee CY, Brody TM. Ouabain binding to (Na+ plus K+)-ATPase. Effects of nucleotide analogues and ethacrynic acid. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 345:102-17. [PMID: 4275608 DOI: 10.1016/0005-2736(74)90250-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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48
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Erdmann E, Schoner W. Ouabain-receptor interactions in (Na+ + K+)-ATPase preparations. II. Effect of cations and nucleotides on rate constants and dissociation constants. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 330:302-15. [PMID: 4272500 DOI: 10.1016/0005-2736(73)90235-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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50
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Colombini M, Johnstone RM. Preparation and properties of the (Na+ + K+)-ATPase of plasma membranes from Ehrlich ascites cells. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 323:69-86. [PMID: 4270852 DOI: 10.1016/0005-2736(73)90432-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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