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Becker EW. Biomechanical model of the P-type ion pumps of the cell. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 1994; 81:21-7. [PMID: 8127374 DOI: 10.1007/bf01138556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The mechanisms of the Na/K pump and of the primary Ca pumps of the cell have not yet been clarified. A biomechanical model of these so-called p-type ion pumps is proposed here. It is based on the assumption that the Na+ and Ca2+ ions are occluded by a contracting protein chain cooperating with the ATPase section of the pump. After transfer of the chain into the region of high Na+ or Ca2+ concentrations, the ions are released through stretching of the chain by the ATPase. In the backward transfer of the chain, a retrograde transport of Na+ ions is prevented through occlusion of K+ ions by another region of the same chain. In the case of Ca2+ ions, a similar effect is expected from hydrated Mg2+ ions. The two sections of the chain discriminate between the electrical field strength at the surface and the polarizability of the ions. The most likely mechanism for the transfer of the ion-binding chain is considered to involve a thermally induced transition of a pump dimer between two almost equivalent stable orientations in the membrane.
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Affiliation(s)
- E W Becker
- Institut für Mikrostrukturtechnik der Universität Karlsruhe
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3
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The interaction of fluorescein isothiocyanate with the ryanodine receptor/Ca2+ release channel of sarcoplasmic reticulum. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)54086-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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4
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Ide T, Morita T, Kawasaki T, Taguchi T, Kasai M. Purification of a K(+)-channel protein of sarcoplasmic reticulum by assaying the channel activity in the planar lipid bilayer system. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1067:213-20. [PMID: 1878373 DOI: 10.1016/0005-2736(91)90046-b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A K(+)-channel protein of the sarcoplasmic reticulum (SR) was purified by assaying the channel activity in a planar lipid bilayer system. The light fraction of SR vesicles was solubilized in 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) and fractionated by an anion-exchange chromatography and followed by gel filtration chromatography and affinity chromatography with concanavalin A. All fractions in each steps were mixed with asolectin solubilized in CHAPS and reconstituted into vesicles by dialysis. The channel activity of each fraction was assayed after the reconstituted vesicles had been fused into a planar lipid bilayer. The final fraction which showed the K(+)-channel activity contained only 100 kDa protein in a silver-stained gel after SDS-PAGE and an anti-Ca(2+)-ATPase antibody did not recognize the protein. The characteristics of the K(+)-channel were identical to those observed in native SR vesicles when using the same method. The channel showed a single-channel conductance of 120 pS in 0.1 M KCl and marked voltage dependence. The channel did not permeate Ca2+ and Cl- and was blocked by neomycin B.
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Affiliation(s)
- T Ide
- Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University, Japan
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Ide T, Sakamoto H, Morita T, Taguchi T, Kasai M. Purification of a Cl-(-)channel protein of sarcoplasmic reticulum by assaying the channel activity in the planar lipid bilayer system. Biochem Biophys Res Commun 1991; 176:38-44. [PMID: 1708250 DOI: 10.1016/0006-291x(91)90886-c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A Cl- channel protein of sarcoplasmic reticulum (SR) was purified by assaying the channel activity in a planar lipid bilayer system. The light fraction of SR vesicles was solubilized in CHAPS and fractioned by anion exchange, gel filtration, and affinity chromatography with concanavalin A. All fractions in each step were reconstituted into vesicles with asolectin by dialysis and their channel activities were assayed after the vesicles had been fused into a planar lipid bilayer. A 100-kDa protein, different from Ca2(+)-ATPase, was found to form anion channels.
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Affiliation(s)
- T Ide
- Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University, Japan
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6
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Villalobo A. Reconstitution of ion-motive transport ATPases in artificial lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1017:1-48. [PMID: 1693288 DOI: 10.1016/0005-2728(90)90176-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Villalobo
- Instituto de Investigaciones Biomédicas, C.S.I.C., Madrid, Spain
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7
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le Maire M, Lund S, Viel A, Champeil P, Moller JV. Ca2(+)-induced conformational changes and location of Ca2+ transport sites in sarcoplasmic reticulum Ca2(+)-ATPase as detected by the use of proteolytic enzyme (V8). J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)40165-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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8
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Clarke DM, Maruyama K, Loo TW, Leberer E, Inesi G, MacLennan DH. Functional Consequences of Glutamate, Aspartate, Glutamine, and Asparagine Mutations in the Stalk Sector of the Ca2+-ATPase of Sarcoplasmic Reticulum. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60455-7] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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9
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Structural and Functional Correlation of the Trypsin-digested Ca2+ Release Channel of Skeletal Muscle Sarcoplasmic Reticulum. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)94245-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Stoichiometry and mapping of the nucleotide sites in sarcoplasmic reticulum ATPase with the use of UTP. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)81613-7] [Citation(s) in RCA: 13] [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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11
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Török K, Trinnaman BJ, Green NM. Tryptic cleavage inhibits but does not uncouple Ca2+ATPase of sarcoplasmic reticulum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 173:361-7. [PMID: 2966067 DOI: 10.1111/j.1432-1033.1988.tb14006.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Sarcoplasmic reticulum Ca2+ATPase is cleaved by trypsin at two sites, T1 and T2. Cleavage at T1 is complete, whereas only about 50% of the Ca2+ATPase is digested at the T2 site. In the absence of Ca2+ ionophor, Ca2+-ATPase activity of the digested enzyme remains virtually unchanged. In the presence of Ca2+ ionophor, however, the calculated specific activity of the doubly cleaved Ca2+ATPase is decreased by about 40%. The decrease in Ca2+ transport activity is much more rapid than cleavage of the T2 site, and could be correlated with an increased leak of Ca2+ from the digested vesicles. We obtained evidence that this leakiness is independent of the digestion of the Ca2+ATPase itself and is presumably due to the digestion of some other components of the sarcoplasmic reticulum vesicles. Examination of steady-state phosphoenzyme levels resulting from phosphorylation by ATP and Pi, or dephosphorylation by ADP or ADP/EGTA revealed no difference between the digested and the undigested Ca2+ATPase indicating no change in the equilibria caused by the T2 cleavage. Analysis of the substrate concentration dependence of the Ca2+ATPase activity also led to the conclusion that the digestion at T2 reduced the Vmax of ATP hydrolysis but leaves the Km unchanged. The above results are consistent with the model that cleavage at the T2 site reduces the turnover rate of the Ca2+ATPase reaction cycle by about 40% by slowing down or altering the rate-limiting step without affecting the equilibrium constants of the examined steps. We found no evidence of true uncoupling of Ca2+ transport from ATP hydrolysis correlated with cleavage at the T2 site.
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Affiliation(s)
- K Török
- Laboratory of Protein Structure, National Institute for Medical Research, London, England
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12
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Trypsin-induced calcium efflux from sarcoplasmic reticulum: Evidence for the involvement of the (Ca2++Mg2+)-ATPase. J Membr Biol 1987. [DOI: 10.1007/bf02209150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Squier T, Bigelow D, Garcia de Ancos J, Inesi G. Localization of site-specific probes on the Ca-ATPase of sarcoplasmic reticulum using fluorescence energy transfer. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61259-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Biophysical Aspects of Ca2+ - Transport Sites in Skeletal and Cardiac Sarcoplasmic Reticulum (Ca2+ + Mg2+)-ATPase. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/978-1-4613-2053-1_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Scott TL. Distances between the functional sites of the (Ca2+ + Mg2+)-ATPase of sarcoplasmic reticulum. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)38583-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Amino-acid sequence of a Ca2+ + Mg2+-dependent ATPase from rabbit muscle sarcoplasmic reticulum, deduced from its complementary DNA sequence. Nature 1985; 316:696-700. [PMID: 2993904 DOI: 10.1038/316696a0] [Citation(s) in RCA: 869] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have cloned and sequenced complementary DNA encoding a Ca2+-ATPase of rabbit muscle sarcoplasmic reticulum. We propose a model of the protein which has 3 cytoplasmic domains joined to a set of 10 transmembrane helices by a narrow, penta-helical stalk. In this model, ATP bound to one cytoplasmic domain would phosphorylate an aspartate in an adjoining cytoplasmic domain, inducing translocation of Ca2+ from binding sites on the stalk.
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Sussman MR. Purification of the Neurospora crassa plasma membrane H+-ATPase by high-pressure liquid chromatography in the presence of sodium dodecyl sulfate. Anal Biochem 1984; 142:210-4. [PMID: 6240211 DOI: 10.1016/0003-2697(84)90540-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Current methods for purifying the Mr 100,000 H+-ATPase from the plasma membrane of fungi and higher plants rely on detergent solubilization followed by density gradient centrifugation. The procedure yields catalytically active enzyme of high purity but takes several days, and the yields are low. For chemical studies on the primary structure of this enzyme, an alternative more rapid procedure was sought. In this paper a method which uses a high-performance gel filtration column in the presence of sodium dodecyl sulfate to purify nanomole quantities of the enzyme in only 30 min is described. With this procedure the enzyme was isolated free of other protein contaminants, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gel filtration was performed on a high-pressure liquid chromatograph equipped with a diode array spectrophotometric detector, allowing spectral analysis of the membrane proteins. An ultraviolet absorption spectrum of the plasma membrane Mr 104,000 H+-ATPase revealed an absorption peak at ca. 275 nm that is consistent with its content of aromatic amino acids.
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Scott TL, Shamoo AE. Distinction of the roles of the two high-affinity calcium sites in the functional activities of the Ca2+-ATPase of sarcoplasmic reticulum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1984; 143:427-36. [PMID: 6236083 DOI: 10.1111/j.1432-1033.1984.tb08390.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effects of trypsin digestion and low temperature on Ca2+ binding and on Ca2+ activation of ATP hydrolysis by the high-affinity transport sites of the Ca2+, Mg2+-ATPase of sarcoplasmic reticulum were examined. Sarcoplasmic reticulum vesicles contain 0.7-1.1 high-affinity Ca2+ sites per 10(5) g sarcoplasmic reticulum with K = 3-5 X 10(5) M-1, as well as sites of lower affinity. The first cleavage of the ATPase with trypsin (TD1) has no effect on the binding properties of the high affinity sites. The second tryptic cleavage (TD2) decreases the affinity of the high sites to K = 3 X 10(4) M-1 with conservation of the total number of sites. The purified ATPase contains 1.6-2.0 high affinity Ca2+ sites per 10(5) g protein when measured at 23 degrees C, while at 0-4 degrees C there is approximately equal to 1 high-affinity (K = 5 - 10 X 10(5) M-1) affinity site and approximately equal to 1 intermediate-affinity (K = 3 X 10(4) M-1) site per 10(5) g. Trypsin digestion to the point of TD1 has no effect on either the number or the binding constants of the high-affinity sites. Upon TD2 cleavage, one of the sites is converted to the intermediate-affinity state, while the other remains at high affinity. After TD2 modification of the enzyme both of the sites are in the intermediate affinity state at 4 degrees C. On the basis of the binding data, several models for the roles of the Ca2+ sites in the activation of ATP hydrolysis are derived. The results are summarized by a scheme in which the two high-affinity Ca2+ sites are heterogeneous with respect to sensitivity to temperature and to TD2 modification. The results of this and a previous study [Scott, T. L. and Shamoo, A. E. (1982) J. Membr. Biol. 64, 137-144] indicate that while occupation of either of the two Ca2+ sites can stimulate ATP hydrolysis, the site which is sensitive to TD2 is essential for the coupling of hydrolysis to Ca2+ transport.
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Herrmann TR, Shamoo AE. Ionophorous properties of the 13 000-Da fragment from sarcoplasmic reticulum (Ca2+ + Mg2+)-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 732:647-50. [PMID: 6135449 DOI: 10.1016/0005-2736(83)90242-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The 25 000-Da tryptic fragment from rabbit muscle sarcoplasmic reticulum (Ca2+ + Mg2+)-ATPase was subjected to cyanogen bromide digestion, and the four fragments isolated. Only the 13 000-Da fragment induced ionophorous activity in planar thin lipid membranes made with 5:1 (w/w) phosphatidylcholine/cholesterol in decane. The membranes became cation selective, with a selectivity sequence among divalent of Mn2+ greater than Ca2+ greater than Ba2+ greater than Sr2+ greater than Mg2+. This is different from that of the 25 000-Da fragment (A.E. Shamoo, 1978, J. Memb. Biol. 43, 227-242), it's 'parent' 55 000-Da fragment, and the intact enzyme, all of which have the same selectivity sequence. The inhibitory effects of Hg2+, Cd2+ and Zn2+ were also examined. All were inhibitory, with Zn2+ being the most effective of these. The heavy-metal-induced inhibition of Ca2+ conductance could be reversed by selective chelation of the heavy metals by EDTA. From changes in the selectivity as well as changes in heavy-metal-induced inhibition behavior, we conclude that the ion transport site of the 13 000-Da fragment may not be the same site as that of the parent fragment. It is either a different site altogether or has been physically modified by peptide cleavage.
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Toogood KC, Folsom B, Topping T, McCutchan H, Dolejsi MJ, Johns S, Stuart G, Dunker AK. Evidence that trypsin digestion exposes a channel in the sarcoplasmic reticulum membrane. MEMBRANE BIOCHEMISTRY 1983; 5:49-75. [PMID: 6316107 DOI: 10.3109/09687688309149633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We present evidence that proteolytic digestion of sarcoplasmic reticulum membranes with trypsin exposes an ionophore that is capable of translocating calcium across the membrane of preloaded vesicles. Net transport of calcium appears to stop when the chemical potential of the ion on both sides of the membrane is equal. The temperature coefficient of steady-state leakage suggests that the ionophore is of the channel or pore type. We suggest that tryptic digestion exposes a channel in sarcoplasmic reticulum membranes through which calcium, and perhaps other ions as well, can diffuse down concentration gradients.
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Farley RA. Identification of hydrophobic regions of the calcium-transport ATPase from sarcoplasmic reticulum after photochemical labeling with adamantane diazirine. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1983; 15:1423-7. [PMID: 6228448 DOI: 10.1016/0020-711x(83)90074-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The Ca-ATPase from skeletal muscle sarcoplasmic reticulum was labeled with [3H]adamantane diazirine. Adamantane diazirine is a hydrophobic photoactivated probe that partitions into the cell membrane and can be used to identify regions of proteins that are embedded within the membrane. Digestion of the labeled protein with trypsin and separation of the labeled tryptic fragments by SDS-polyacrylamide-gel electrophoresis indicated that all of the major tryptic fragments were labeled by the probe. The presence of glutathione in the sample buffer during photolysis did not alter the pattern of labeling, indicating that adamantane diazirine labeled the Ca-ATPase from within the lipid bilayer. These results indicate that the Ca-ATPase polypeptide must cross the membrane at least 3 times.
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Scott TL, Shamoo AE. Disruptiin of energy transductiin in sarcoplasmic reticulum by trypsin cleavage of (Ca2+ + Mg2+)-ATPase. J Membr Biol 1982; 64:137-44. [PMID: 6120240 DOI: 10.1007/bf01870879] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Berman MC. Energy coupling and uncoupling of active calcium transport by sarcoplasmic reticulum membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 694:95-121. [PMID: 6127107 DOI: 10.1016/0304-4157(82)90015-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Serpersu EH, Kirch U, Schoner W. Demonstration of a stable occluded form of Ca2+ by the use of the chromium complex of ATP in the Ca2+-ATPase of sarcoplasmic reticulum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 122:347-54. [PMID: 6460621 DOI: 10.1111/j.1432-1033.1982.tb05887.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Lebedev AV, Levitsky DO, Loginov VA. Oxygen as an inductor of divalent cation permeability through biological and model lipid membranes. ADVANCES IN MYOCARDIOLOGY 1982; 3:425-438. [PMID: 6302785 DOI: 10.1007/978-1-4899-5561-6_42] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The action of lipid hydroperoxides (LH), which are primary products of lipid oxidation, on cation permeability through bilayer lipid membranes (BLM) and sarcoplasmic reticulum (SR) membranes was investigated. Bilayer lipid membranes prepared from unoxidized phosphatidyl choline (PC) plus cholesterol or from total phospholipids extracted from SR vesicles possessed low cation permeability. Lipid oxidation induced by Fe2+-ascorbate led to a sharp increase in the calcium current through the BLM and to a considerable increase in the concentration of LH products. Further spontaneous lipid oxidation to final products led to decrease of LH concentration and calcium current through the BLM. The Ca2+ conductivity of the BLM increased more strongly if Fe2+-ascorbate was added to both sides of the BLM. The LH-induced cation permeability decreased in the sequence Ca2+, Mg2+, Ba2+, Sr2+, K+, Rb+, Cs+, NH4+, Na+, Li+. This is similar to the order of cation permeability known as the biological row of permeability and holds for BLMs formed from various lipids. In addition, Fe2+-ascorbate induced calcium ion leakage from SR vesicles isolated from guinea pig heart or from rabbit white skeletal muscle. It is proposed that the lipid hydroperoxide molecules form the simplest channel in lipid membranes, providing the permeability for calcium and other divalent cations.
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Haynes DH, Werber MM. Inhibition of the Ca2+-Mg2+ ATPase of sarcoplasmic reticulum by Co-(phen)-ATP. MEMBRANE BIOCHEMISTRY 1982; 4:247-57. [PMID: 6129563 DOI: 10.3109/09687688209065434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Active Ca2+ transport in sarcoplasmic reticulum derived from skeletal muscle is shown to be inhibited by an ATP derivative Co(III)-phenanthroline-ATP. The inhibition is by competition for the MgATP binding site on the Ca2+-ATPase pump molecule. For preincubation times of 30 min or less, no quasicovalent bonds are established between the inhibitor and the ATPase. The apparent dissociation constant for the enzyme-inhibitor complex is 0.27 mM), a value close to the apparent Km and Ki values for MgATP (0.24 mM) and CoATP (0.14 mM). Addition of Co-(phen)-ATP to sarcoplasmic reticulum after maximal Ca2+ uptake has been achieved causes the release of the accumulated Ca2+. Under the experimental conditions chosen, the release occurs in two phases: one with a half-time of less than 2 sec and one with a half-time of 17 to 50 sec. The implications of these findings to the ATPase active transport mechanism are discussed.
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A fluorescence probe study of the phosphorylation reaction of the calcium ATPase of sarcoplasmic reticulum. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68769-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Nicholls P. Liposomes-as artificial organelles, topochemical matrices, and therapeutic carrier systems. INTERNATIONAL REVIEW OF CYTOLOGY. SUPPLEMENT 1981; 12:327-88. [PMID: 7019121 DOI: 10.1016/b978-0-12-364373-5.50018-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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MacLennan DH, Reithmeier RA, Shoshan V, Campbell KP, LeBel D, Herrmann TR, Shamoo AE. Ion pathways in proteins of the sarcoplasmic reticulum. Ann N Y Acad Sci 1980; 358:138-48. [PMID: 6259987 DOI: 10.1111/j.1749-6632.1980.tb15392.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In summary, we have begun to characterize three different ion pathways in the sarcoplasmic reticulum. Ca2+-ionophoric activity has been traced to a 13,000-dalton CNBr fragment localized at the amino terminus of the ATPase molecule... The pathway involved in Ca2+ release can be distinguished from the pathway involved in Ca2+ uptake by its insensitivity to quercetin. An anion pathway is sensitive to DIDS and appears to be localized in the ATPase molecule
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Pick U, Karlish SJ. Indications for an oligomeric structure and for conformational changes in sarcoplasmic reticulum Ca2+-ATPase labelled selectively with fluorescein. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 626:255-61. [PMID: 6450619 DOI: 10.1016/0005-2795(80)90216-0] [Citation(s) in RCA: 171] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Fluorescein isothiocyanate is a highly specific inhibitor of the Ca2+-ATPase from sarcoplasmic reticulum. The Ca2+ pumping is inhibited completely at a fluorescein isothiocyanate concentration half that of the ATPase protein, indicating that the protein is at least a dimer. ATP protected specifically against fluorescein isothiocyanate inhibition, indicating that fluorescein isothiocyanate may react at the nucleotide binding site of the ATPase (probably with a reactive lysine residue). The fluorescein is incorporated almost exclusively into the 105 kdalton catalytic polypeptide of the ATPase and digestion by trypsin gives rise to a fluorescein-labelled 45 kdalton fragment. Conformational changes induced by addition of Ca can be studied conveniently with the fluorescein-labelled ATPase.
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Tong SW. Studies on the structure of the calcium-dependent adenosine triphosphatase from rabbit skeletal muscle sarcoplasmic reticulum. Arch Biochem Biophys 1980; 203:780-91. [PMID: 6450567 DOI: 10.1016/0003-9861(80)90239-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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36
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Inesi G, Kurzmack M, Nakamoto R, de Meis L, Bernhard S. Uncoupling of calcium control and phosphohydrolase activity in sarcoplasmic reticulum vesicles. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43696-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Alignment of the major tryptic fragments of the adenosine triphosphatase from sarcoplasmic reticulum. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43605-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Gitler C, Bercovici T. Use of lipophilic photoactivatable reagents to identify the lipid-embedded domains of membrane proteins. Ann N Y Acad Sci 1980; 346:199-211. [PMID: 6930182 DOI: 10.1111/j.1749-6632.1980.tb22100.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Bailin G. Dinitrophenylation of rabbit skeletal sarcoplasmic reticulum ATPase protein. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 623:213-24. [PMID: 6445758 DOI: 10.1016/0005-2795(80)90023-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The ATPase (ATP phosphohydrolase (EC 3.6.1.3)) protein of rabbit skeletal sarcoplasmic reticulum rapidly incorporated three mol of 1-fluoro-2,4-dinitrobenzene per 10(5) g of protein with little change in the Ca2+-dependent ATPase activity. When 2 additional mol of the reagent were bound the Ca2+-dependent ATPase activity was inhibited. The dinitrophenyl group was located mainly in the ATPase protein and a small amount of the label was found in the proteolipid component of the ATPase preparation as judged by dissociation experiments in sodium dodecyl sulfate. Cysteine and tyrosine residues were dinitrophenylated in the modified ATPase protein. Thiolysis of the dinitrophenylated ATPase protein with 2-mercaptoethanol under various conditions did not restore the Ca2+-dependent ATPase activity. Solubilization of the ATPase protein with sodium deoxycholate increased the reactivity of the reagent and the Ca2+-dependent ATPase activity was inhibited to a greater extent. Dinitrophenylation of the ATPase protein was Ca2+-dependent; in the presence of high Ca2+ the incorporation increased by 50% and a large decrease in the Ca2+-ATPase activity was noted. The half-maximal changes for the incorporation of the reagent and the inhibition of the Ca2+-ATPase activity occurred at 3--4 microgram Ca2+-concentration, consistent with the binding of Ca2+ to high affinity sites on the ATPase protein. These results indicate that the ATPase protein as a Ca2+-free and a Ca2+-bound conformation. The reagent, 1-fluoro-2,4-dinitrobenzene reacts differentially and thus characterizes these two conformations.
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40
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Criteria for the Reconstitution of Ion Transport Systems. ACTA ACUST UNITED AC 1980. [DOI: 10.1016/s0070-2161(08)60115-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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41
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Godfraind-De Becker A, Godfraind T. Calcium transport system: a comparative study in different cells. INTERNATIONAL REVIEW OF CYTOLOGY 1980; 67:141-70. [PMID: 6256307 DOI: 10.1016/s0074-7696(08)62428-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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42
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Abramson JJ, Shamoo AE. Anionic detergents as divalent cation ionophores across black lipid membranes. J Membr Biol 1979; 50:241-55. [PMID: 513115 DOI: 10.1007/bf01868891] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Three ionic detergents commonly used in membrane-bound protein isolation and reconstitution experiments, SDS, cholate, and DOC, are shown to act as divalent cation ionophores when incorporated into black lipid membranes made from either oxidized cholesterol or a mixture of phosphatidylcholine and cholesterol (PC/cholesterol = 5:1 mg). At a concentration greater than or equal to 1 microM, SDS shows large selectivity differences between cations and anions and among the different cations tested (Ba2+, Ca2+, Sr2+, Mg2+, and Mn2+). Deoxycholate and cholate at concentrations greater than 4 X 10(-4) M and 10(-3) M, respectively, also act as divalent cation ionophores. The selectivity sequence measured for these two detergents is evidence for a strong ionic interaction between the divalent cation and the anionic charged groups on the detergent. In the case of cholate, the conductance depends on the third or fourth power of the cholate concentration and shows a linear dependence on CaCl2 concentration. The conductance for deoxycholate depends onthe sixth or seventh power of the DOC concentration and is also linearly dependent on the CaCl2 concentration. In an oxidized cholesterol black lipid membrane in the presence of 5 mM CaCl2, small concentrations of LaCl3 (less then 1 microM) inhibit the ionophoric activity of each of the detergents tested. Evidence is presented to show that this inhibitory effect is a nonspecific effect on oxidized cholesterol BLM's, and is not due to a direct effect of La3+ on detergent-mediated transport.
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MacLennan DH, Campbell KP. Structure, function and biosynthesis of sarcoplasmic reticulum proteins. Trends Biochem Sci 1979. [DOI: 10.1016/0968-0004(79)90002-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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44
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Ionophores and Ion Transport Across Natural Membranes. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/b978-0-12-152509-5.50011-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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45
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46
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Reaction Mechanisms for ATP Hydrolysis and Synthesis in the Sarcoplasmic Reticulum. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/b978-0-12-152509-5.50012-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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47
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Abramson JJ, Shamoo AE. Purification and characterization of the 45,000-Dalton fragment from tryptic digestion of (Ca2+ + Mg2+)-adenosine triphosphatase of sarcoplasmic reticulum. J Membr Biol 1978; 44:289-301. [PMID: 156795 DOI: 10.1007/bf01944223] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tryptic digestion of (Ca2+ + Mg2+)-ATPase from sarcoplasmic reticulum of rabbit skeletal muscle has previously been shown to cleave the enzyme initially into a 55,000-dalton fragment and a 45,000-dalton fragment. In the present study the two fragments are solubilized in sodium dodecyl sulfate (SDS) and separated by preparative polyacrylamide gel electrophoresis. The 45,000-dalton fragment is found to be a relatively nonselective, divalent cation-dependent ionophore when incorporated into an oxidized cholesterol membrane (BLM). Ionophoric activity of this fragment is inhibited by low concentrations of LaCl3, HgCl2, and various reducing agents. There appears to be one or two relatively inaccessible disulfide bonds in the 45,000-dalton fragment that are essential for transport. Addition of reducing agents inhibits the ionophoric activity of the succinylated undigested enzyme and the 45,000-dalton fragment, but has no effect on the 55,000-dalton fragment. These experiments imply that the 45,000-dalton fragment and the 55,000-dalton fragment are in a series arrangement in the membrane.
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Shamoo AE. Ionophorous properties of the 20,000-dalton fragment of (Ca2+ + Mg2+)-ATPase in phosphatidylcholine: cholesterol membranes. J Membr Biol 1978; 43:227-42. [PMID: 152358 DOI: 10.1007/bf01933480] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The purified 20,000-dalton fragment of sarcoplasmic reticulum (Ca2+ + Mg2+)-ATPase has been shown by us (A.E. Shamoo, T.E. Ryan, P.S. Stewart, D.H. MacLennan, 1976. J. Biol. Chem. 251:4147) to have Ca2+-selective ionophoric activity. The Ca2+-ionophoric fragment has been purified by either SDS-column chromatography or SDS-preparative gel electrophoresis. The Ca2+-ionophoric fragment has been subjected to prolonged dialysis to insure the removal of bound SDS from the fragment. The selectivity sequence of this fragment in black lipid membranes (BLM) formed from either oxidized cholesterol or phosphatidylcholine/cholesterol is the same, PBa greater than PCa greater than PSr greater than PMg greater than PMn. This selectivity sequence is the same as that for the intact (Ca2+ + Mg2+)-ATPase. Treatment of the fragment with cholate to absolutely insure the removal of bound SDS resulted in the fragment having a selectivity sequence as above except that PMn greater than PMg. This and other data indicate that the 20,000-dalton fragment is the site containing the Ca2+-ionophoric activity of the (Ca2+ + Mg2+)-ATPase.
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Kagawa Y. Reconstitution of the energy transformer, gate and channel subunit reassembly, crystalline ATPase and ATP synthesis. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 505:45-93. [PMID: 30482 DOI: 10.1016/0304-4173(78)90008-3] [Citation(s) in RCA: 198] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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50
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McIntosh D, Berman M. Calcium ion stabilization of the calcium transport system of sarcoplasmic reticulum. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34668-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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