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Dysfunction of SERCA pumps as novel mechanism of methylglyoxal cytotoxicity. Cell Calcium 2018; 74:112-122. [DOI: 10.1016/j.ceca.2018.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/18/2018] [Accepted: 06/18/2018] [Indexed: 01/01/2023]
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2
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Rutin stimulates sarcoplasmic reticulum Ca(2+)-ATPase activity (SERCA1) and protects SERCA1 from peroxynitrite mediated injury. Mol Cell Biochem 2014; 402:51-62. [PMID: 25547066 DOI: 10.1007/s11010-014-2313-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/20/2014] [Indexed: 01/13/2023]
Abstract
In this study we analyzed the protective action of the flavonoid rutin on peroxynitrite (ONOO(-)) mediated impairment of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1 isoform), especially related to posttranslational and conformational changes. Rutin concentration dependently protected ONOO(-) induced SERCA1 activity decrease with effective concentration EC50 of 18 ± 1.5 µM. Upon treatment with ONOO(-), this flavonoid also prevented SERCA1 from thiol group oxidation and significantly reduced tyrosine nitration and protein carbonyl formation. In the absence of ONOO(-), rutin (250 and 350 µM) stimulated SERCA1 activity at 2.1 mM [ATP] and 10 µM [Ca(2+)]free. According to changes in the kinetic parameters V max and K m with regard to [ATP], rutin (250 µM) increased the rate of enzyme catalysis and decreased the affinity of SERCA1 to ATP. FITC fluorescence decreased in the presence of rutin (150 and 250 µM), indicating conformational changes in the cytosolic ATP binding region of SERCA1. In silico study confirmed the binding of rutin in the cytosolic region of SERCA1, in the vicinity of the ATP binding site. Residue Glu183 localized within the conserved TGES loop was identified to play a key role in rutin-SERCA1 interaction (H-bond length of 1.7 Å), elucidating the ability of rutin to affect the affinity of SERCA1 to ATP. The binding of rutin in the proximity of Lys515 is likely to cause a decrease in FITC fluorescence.
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Bockelmann S, Menche D, Rudolph S, Bender T, Grond S, von Zezschwitz P, Muench SP, Wieczorek H, Huss M. Archazolid A binds to the equatorial region of the c-ring of the vacuolar H+-ATPase. J Biol Chem 2010; 285:38304-14. [PMID: 20884613 DOI: 10.1074/jbc.m110.137539] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The macrolactone archazolid is a novel, highly specific V-ATPase inhibitor with an IC(50) value in the low nanomolar range. The binding site of archazolid is presumed to overlap with the binding site of the established plecomacrolide V-ATPase inhibitors bafilomycin and concanamycin in subunit c of the membrane-integral V(O) complex. Using a semi-synthetic derivative of archazolid for photoaffinity labeling of the V(1)V(O) holoenzyme we confirmed binding of archazolid to the V(O) subunit c. For the plecomacrolide binding site a model has been published based on mutagenesis studies of the c subunit of Neurospora crassa, revealing 11 amino acids that are part of the binding pocket at the interface of two adjacent c subunits (Bowman, B. J., McCall, M. E., Baertsch, R., and Bowman, E. J. (2006) J. Biol. Chem. 281, 31885-31893). To investigate the contribution of these amino acids to the binding of archazolid, we established in Saccharomyces cerevisiae mutations that in N. crassa had changed the IC(50) value for bafilomycin 10-fold or more and showed that out of the amino acids forming the plecomacrolide binding pocket only one amino acid (tyrosine 142) contributes to the binding of archazolid. Using a fluorescent derivative of N,N'-dicyclohexylcarbodiimide, we found that the binding site for archazolid comprises the essential glutamate within helix 4 of subunit c. In conclusion the archazolid binding site resides within the equatorial region of the V(O) rotor subunit c. This hypothesis was supported by an additional subset of mutations within helix 4 that revealed that leucine 144 plays a role in archazolid binding.
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Affiliation(s)
- Svenja Bockelmann
- Universität Osnabrück, Fachbereich Biologie/Chemie, Abteilung Tierphysiologie, Barbarastrasse 11, 49069 Osnabrück, Germany
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Augustyniak A, Bartosz G, Čipak A, Duburs G, Horáková L, Łuczaj W, Majekova M, Odysseos AD, Rackova L, Skrzydlewska E, Stefek M, Štrosová M, Tirzitis G, Venskutonis PR, Viskupicova J, Vraka PS, Žarković N. Natural and synthetic antioxidants: An updated overview. Free Radic Res 2010; 44:1216-62. [DOI: 10.3109/10715762.2010.508495] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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6
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Tupling R, Green H, Senisterra G, Lepock J, McKee N. Ischemia-induced structural change in SR Ca2+-ATPase is associated with reduced enzyme activity in rat muscle. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1681-8. [PMID: 11641141 DOI: 10.1152/ajpregu.2001.281.5.r1681] [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: 11/22/2022]
Abstract
In this study, we employed an in vivo model of prolonged ischemia in rat skeletal muscle to investigate the hypothesis that structural modifications to the sarcoplasmic reticulum (SR) Ca2+-ATPase can explain the alterations in Ca2+-ATPase activity that occur with ischemia. To induce total ischemia, a tourniquet was placed around the upper hindlimb in 27 female Sprague-Dawley rats weighing 256 +/- 6.7 g (mean +/- SE) and was inflated to 350 mmHg for 4 h. The contralateral limb served as control (C) to the ischemic limb (I), and the limbs of animals killed immediately after anesthetization served as a double control (CC). Mixed gastrocnemius and tibialis anterior muscles were sampled and used for SR vesicle preparation. Maximal Ca2+-ATPase activity (micromol x g protein(-1) x min(-1)) of C (15,802 +/- 1,246) and I (11,609 +/- 1,029) was 90 and 73% (P < 0.05) of CC (17,562 +/- 1,682), respectively. No differences were found between groups in either the Hill coefficient or the free Ca2+ at half-maximal activity. The fluorescent probes, FITC and N-cyclohexyl-N'-(dimethylamino-alpha-naphthyl) carbodiimide, used to assess structural alterations in the regions of the ATP binding site and the Ca2+ binding sites of the Ca2+-ATPase, respectively, indicated a 26% reduction (P < 0.05) in FITC binding capacity (absolute units) in I (0.22 +/- 0.01) compared with CC (0.29 +/- 0.02) and C (0.29 +/- 0.03). Our results suggest that the reduction in maximal SR Ca2+-ATPase activity in SR vesicles with ischemia is related to structural modification in the region of the nucleotide binding domain by mechanisms that are as yet unclear.
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Affiliation(s)
- R Tupling
- Department of Kinesiology, University of Waterloo, Waterloo N2L 3G1, Ontario, Canada M5S 1A1
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7
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Wang Y, Obungu V, Beattie DS. Dicyclohexylcarbodiimide inhibits proton pumping in ubiquinol:cytochrome c oxidoreductase of Rhodobacter sphaeroides and binds to aspartate-187 of cytochrome b. Arch Biochem Biophys 1998; 352:193-8. [PMID: 9587406 DOI: 10.1006/abbi.1998.0590] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In recent studies we reported that dicyclohexylcarbodiimide (DCCD) inhibited proton translocation in ubiquinol:cytochrome c oxidoreductase (cytochrome bc1 complex) from yeast mitochondria where it was bound to aspartate-160 of cytochrome b. In the current study, we report that DCCD and its fluorescent analogue, N-cyclohexyl-N'-[4-(dimethylamino)naphthyl]-carbodiimide (NCD-4), inhibit 50-60% proton pumping in the cytochrome bc1 complex of the bacterium Rhodobacter sphaeroides with a 20% inhibition of electron transfer activity. Radioactive DCCD is bound exclusively to cytochrome b at aspartate-187, which is located at the C-terminal region of the CD loop connecting membrane-spanning helices C and D of cytochrome b. Fluorescent studies with NCD-4 revealed that aspartate-187 is located in a mildly hydrophobic pocket in the bc1 complex at a distance of 2-3 A from the surface of the membrane.
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Affiliation(s)
- Y Wang
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown 26505-9142, USA
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Rabon EC, Hoggatt M, Smillie K. Transmembrane carboxyl residues are essential for cation-dependent function in the gastric H,K-ATPase. J Biol Chem 1996; 271:32137-46. [PMID: 8943267 DOI: 10.1074/jbc.271.50.32137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The K+-dependent ATPase activity of the H,K-ATPase was irreversibly inhibited by the carboxyl activating reagent, dicyclohexylcarbodiimide (DCCD). The inhibition was first order and displayed a concentration dependence with the K0.5 (DCCD) = 0.65 +/- 0.04 mM. KCl protected 70% of the ATPase activity from DCCD-dependent inhibition in a concentration-dependent manner with a K0.5 (K+) = 0.58 +/- 0.1 mM KCl. DCCD modification selectively inhibited the K+-dependent rather than ATP-dependent partial reactions including eosin fluorescence responses and ligand-stabilized initial tryptic cleavage patterns of the membrane-associated enzyme. DCCD modification also inhibited the binding of 86Rb+ and the fluorescent responses of the K+-competitive, fluorescent inhibitor 1-(2-methylphenyl)-4-methylamino-6-methyl-2, 3-dihydropyrrolo[3,2-c]quinoline. [14C]DCCD was incorporated into the H,K-ATPase in a time course identical to that describing the inactivation of the K+-dependent ATPase activity of the H,K-ATPase. A component of the [14C]DCCD incorporated into the H,K-ATPase was K+-sensitive where K+ reduced the [14C]DCCD incorporated into the enzyme by 1.6 nmol of [14C]DCCD/mg of protein. Membrane-associated tryptic peptides resolved from the [14C]DCCD-modified H,K-ATPase exhibited various K+ sensitivities with peptides at 23, 9.6, 8.2, 7.1, and 6.1 kDa containing 10-78%, 23-52%, 24-36%, 2%, and 3-4% K+-sensitivity, respectively. The N-terminal sequence of the K+-sensitive, approximately 23- and 9.6-kDa peptides was LVNE857, a C-terminal fragment of the ATPase alpha-subunit. The mass of the smaller peptide limited the residue assignment to the transmembrane M7/M8 domains and an intervening extracytoplasmic loop. An N-terminal sequence, SD840IM, was obtained from a 3.3-kDa, [14C]DCCD-labeled peptide resolved from a V8 digest of the partially purified alpha-subunit. This mass was sufficient to include LVNE but would exclude M8 and the intervening loop between M7 and M8. Glu857 is a unique residue present in each of the proteolytic preparations of the H,K-ATPase modified by [14C]DCCD. These data provide functional evidence of the selective inactivation of the K+-dependent partial reactions of the H,K-ATPase and show that Glu857 located at the M7 boundary in the C terminus of the pump molecule is a significant site of DCCD modification. These data are interpreted to indicate that this carboxyl residue is important for cation binding function.
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Affiliation(s)
- E C Rabon
- Tulane University Medical Center and Veterans Administration Center, New Orleans, Louisiana 70112, USA
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Møller JV, Juul B, le Maire M. Structural organization, ion transport, and energy transduction of P-type ATPases. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1286:1-51. [PMID: 8634322 DOI: 10.1016/0304-4157(95)00017-8] [Citation(s) in RCA: 563] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- J V Møller
- Department of Biophysics, University of Aarhus, Denmark
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Musser SM, Larsen RW, Chan SI. Fluorescence quenching of reconstituted NCD-4-labeled cytochrome c oxidase complex by DOXYL-stearic acids. Biophys J 1993; 65:2348-59. [PMID: 8312474 PMCID: PMC1225976 DOI: 10.1016/s0006-3495(93)81309-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
It has been known for some time that dicyclohexylcarbodiimide (DCCD) inhibits the proton translocation function of the cytochrome c oxidase complex (CcO) and that there is one major site in subunit III which is modified upon reaction with DCCD (Glu-90 for the bovine enzyme). We have examined the reaction of bovine CcO with N-cyclohexyl-N'-(4-dimethylamino-alpha-napthyl)carbodiimide (NCD-4), a fluorescent analog of DCCD. NCD-4 labeling of CcO is strongly inhibited by DCCD implicating Glu-90 of subunit III as the site of chemical modification by NCD-4. The fluorescence of reconstituted NCD-4-labeled bovine CcO is strongly quenched by hydrophobic nitroxides, whereas hydrophilic nitroxides and iodide ions have a reduced quenching ability. It is concluded that the Glu-90 of subunit III resides near the protein-lipid interface of the membrane spanning region of the enzyme. Different quenching abilities of 5-, 7-, 10-, 12-, and 16-4,4-dimethyl-3-oxazolinyloxy-stearic acids suggest that the NCD-4 label is located in the membrane bilayer in the region near the middle of the hydrocarbon tail of stearic acid. In light of these results, it is unlikely that Glu-90 is part of a proton channel that is associated with the proton pumping machinery of the enzyme but the outcome of this study does not eliminate an allosteric regulatory role for this residue.
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Affiliation(s)
- S M Musser
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125
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12
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Sumbilla C, Lu L, Lewis D, Inesi G, Ishii T, Takeyasu K, Feng Y, Fambrough D. Ca(2+)-dependent and thapsigargin-inhibited phosphorylation of Na+,K(+)-ATPase catalytic domain following chimeric recombination with Ca(2+)-ATPase. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)36908-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [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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Wang Y, Beattie DS. Topographical organization of cytochrome b6 in the thylakoid membrane of spinach chloroplasts determined by fluorescence studies with N-cyclohexyl-N'-[4-(dimethylamino)naphthyl]carbodiimide. Biochemistry 1993; 32:9586-91. [PMID: 8373766 DOI: 10.1021/bi00088a010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In a recent study [Wang & Beattie (1992) Biochemistry 31, 8445-8459], we reported that dicyclohexylcarbodiimide (DCCD) was bound to either aspartate-155 or glutamate-166 localized in an amphiphilic, non-membrane-spanning, helix of cytochrome. Moreover, DCCD inhibits proton translocation in a cytochrome bf complex reconstituted into proteoliposomes without significant inhibition of electron transfer, suggesting that the helix containing aspartate-155 and glutamate-166 may play a role in proton movements. In order to explore the environment of this amphiphilic helix, we employed a fluorescent derivative of DCCD, N-cyclohexyl-N'-[4-(dimethylamino)naphthyl]carbodiimide (NCD-4). After incubation of NCD-4 with a cytochrome bf complex isolated from spinach chloroplasts, a fluorescent compound was formed with a 331-nm excitation peak and 440-nm emission peak. NCD-4 was selectively bound to cytochrome b6 and inhibited proton translocation with only a minimal inhibitory effect on electron transfer in the cytochrome bf complex reconstituted into proteoliposomes. Exhaustive digestion of the NCD-4-labeled cytochrome b6 with trypsin resulted in the formation of a single 6-kDa fluorescent peptide with similar properties to the peptide labeled with radioactive DCCD. The fluorescence of NCD-4 bound to the cytochrome bf complex reconstituted into proteoliposomes was quenched by CAT-16, an amphiphilic spin label that intercalates at the membrane surface, as well as by nitroxide derivatives of stearic acid in the order 5-doxylstearic acid > 7-doxylstearic acid > 12-doxylstearic acid. At higher concentrations, the hydrophilic membrane-impermeant quenchers, CAT-1 and D-569, also quenched the fluorescence of NCD-4.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- Y Wang
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown 26506-9142
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14
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Beattie DS. A proposed pathway of proton translocation through the bc complexes of mitochondria and chloroplasts. J Bioenerg Biomembr 1993; 25:233-44. [PMID: 8394319 DOI: 10.1007/bf00762585] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The cytochrome bc complexes of the electron transport chain from a wide variety of organisms generate an electrochemical proton gradient which is used for the synthesis of ATP. Proton translocation studies with radiolabeled N,N'-dicyclohexylcarbodiimide (DCCD), the well-established carboxyl-modifying reagent, inhibited proton-translocation 50-70% with minimal effect on electron transfer in the cytochrome bc1 and cytochrome bf complexes reconstituted into liposomes. Subsequent binding studies with cytochrome bc1 and cytochrome bf complexes indicate that DCCD specifically binds to the subunit b and subunit b6, respectively, in a time and concentration dependent manner. Further analyses of the results with cyanogen bromide and protease digestion suggest that the probable site of DCCD binding is aspartate 160 of yeast cytochrome b and aspartate 155 or glutamate 166 of spinach cytochrome b6. Moreover, similar inhibition of proton translocating activity and binding to cytochrome b and cytochrome b6 were noticed with N-cyclo-N-(4-dimethylamino-napthyl)carbodiimide (NCD-4), a fluorescent analogue of DCCD. The spin-label quenching experiments provide further evidence that the binding site for NCD-4 on helix cd of both cytochrome b and cytochrome b6 is localized near the surface of the membrane but shielded from the external medium.
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Affiliation(s)
- D S Beattie
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown 26506-9142
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15
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Bigelow DJ, Inesi G. Contributions of chemical derivatization and spectroscopic studies to the characterization of the Ca2+ transport ATPase of sarcoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1113:323-38. [PMID: 1450205 DOI: 10.1016/0304-4157(92)90005-u] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- D J Bigelow
- Department of Biochemistry, University of Kansas, Lawrence
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16
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Inesi G, Cantilina T, Yu X, Nikic D, Sagara Y, Kirtley ME. Long-range intramolecular linked functions in activation and inhibition of SERCA ATPases. Ann N Y Acad Sci 1992; 671:32-47; discussion 48. [PMID: 1288328 DOI: 10.1111/j.1749-6632.1992.tb43782.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- G Inesi
- Department of Biological Chemistry, School of Medicine, University of Maryland, Baltimore 21201
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17
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Corbalan-Garcia S, Teruel JA, Gomez-Fernandez JC. Characterization of ruthenium red-binding sites of the Ca(2+)-ATPase from sarcoplasmic reticulum and their interaction with Ca(2+)-binding sites. Biochem J 1992; 287 ( Pt 3):767-74. [PMID: 1280106 PMCID: PMC1133074 DOI: 10.1042/bj2870767] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Sarcoplasmic reticulum Ca(2+)-ATPase has previously been shown to bind and dissociate two Ca2+ ions in a sequential mode. This behaviour is confirmed here by inducing sequential Ca2+ dissociation with Ruthenium Red. Ruthenium Red binds to sarcoplasmic reticulum vesicles (6 nmol/mg) with a Kd = 2 microM, producing biphasic kinetics of Ca2+ dissociation from the Ca(2+)-ATPase, decreasing the affinity for Ca2+ binding. Studies on the effect of Ca2+ on Ruthenium Red binding indicate that Ruthenium Red does not bind to the high-affinity Ca(2+)-binding sites, as suggested by the following observations: (i) micromolar concentrations of Ca2+ do not significantly alter Ruthenium Red binding to the sarcoplasmic reticulum; (ii) quenching of the fluorescence of fluorescein 5'-isothiocyanate (FITC) bound to Ca(2+)-ATPase by Ruthenium Red (resembling Ruthenium Red binding) is not prevented by micromolar concentrations of Ca2+; (iii) quenching of FITC fluorescence by Ca2+ binding to the high-affinity sites is achieved even though Ruthenium Red is bound to the Ca(2+)-ATPase; and (iv) micromolar Ca2+ concentrations prevent inhibition of the ATP-hydrolytic capability by dicyclohexylcarbodi-imide modification, but Ruthenium Red does not. However, micromolar concentrations of lanthanides (La3+ and Tb3+) and millimolar concentrations of bivalent cations (Ca2+ and Mg2+) inhibit Ruthenium Red binding as well as quenching of FITC-labelled Ca(2+)-ATPase fluorescence by Ruthenium Red. Studies of Ruthenium Red binding to tryptic fragments of Ca(2+)-ATPase, as demonstrated by ligand blotting, indicate that Ruthenium Red does not bind to the A1 subfragment. Our observations suggest that Ruthenium Red might bind to a cation-binding site in Ca(2+)-ATPase inducing fast release of the last bound Ca2+ by interactions between the sites.
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Affiliation(s)
- S Corbalan-Garcia
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de Murcia, Spain
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18
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Cheng KH, Lepock JR. Inactivation of calcium uptake by EGTA is due to an irreversible thermotropic conformational change in the calcium binding domain of the Ca(2+)-ATPase. Biochemistry 1992; 31:4074-80. [PMID: 1533156 DOI: 10.1021/bi00131a025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Calcium uptake by rabbit skeletal sarcoplasmic reticulum (SR) is inhibited with an effective inactivation temperature (TI) of 37 degrees C in EGTA with no effect on ATPase activity. Since the Ca-ATPase denatures at a much higher temperature (49 degrees C) in EGTA, this suggests that a small or localized conformational change of the Ca-ATPase at 37 degrees C results in inability to accumulate calcium by the SR. Using a fluorescent analogue of dicyclohexylcarbodiimide, N-cyclohexyl-N'-[4-(dimethylamino)-alpha-naphthyl]-carbodiimide (NCD-4), the region of the calcium binding sites of the SR Ca-ATPase was labeled. Steady-state and frequency-resolved fluorescence measurements were subsequently performed on the NCD-4-labeled Ca-ATPase. Site-specific information pertaining to the hydrophobicity and segmental flexibility of the region of the calcium binding sites was derived from the steady-state fluorescence intensity, lifetime, and rotational rate of the covalently bound NCD-4 label as a function of temperature (0-50 degrees C). A reversible transition at approximately 15 degrees C and an irreversible transition at approximately 35 degrees C were deduced from the measured fluorescence parameters. The low-temperature transition agrees with the previously observed break in the Arrhenius plot of ATPase activity of the native Ca-ATPase at 15-20 degrees C. The high-temperature transition conforms well with the conformational transition, resulting in uncoupling of Ca translocation from ATP hydrolysis as predicted from the irreversible inactivation of Ca uptake at 31-37 degrees C in 1 mM EGTA.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K H Cheng
- Department of Physics, Texas Tech University, Lubbock 79409
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19
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Interdependence of Ca2+ occlusion sites in the unphosphorylated sarcoplasmic reticulum Ca(2+)-ATPase complex with CrATP. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50763-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Lalonde RJ, Lepock JR, Kruuv J. Site of freeze-thaw damage and cryoprotection by amino acids of the calcium ATPase of sarcoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1079:128-38. [PMID: 1832965 DOI: 10.1016/0167-4838(91)90117-i] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Ca2+,Mg(2+)-ATPase of skeletal muscle sarcoplasmic reticulum (SR) is irreversibly inactivated by a freeze-thaw (FT) cycle. The membrane does not become more permeable to calcium after a FT cycle, suggesting that the reduced uptake is due to damage to the Ca2+,Mg(2+)-ATPase. Several amino acids, in addition to standard cryoprotectants provide good protection of calcium uptake against FT damage. The amount of protection given by the amino acids is generally inversely proportional to a measure of hydrophobicity, the mean fractional area loss upon incorporation in globular proteins of the amino acid side chain. Unlike the case for cells, glutamine and dimethyl sulfoxide do not act independently as cryoprotectants for SR calcium ATPase. When the protein is exposed to multiple FT cycles, the amount of inactivation is exponentially proportional to the number of FT cycles. This is true for both protected and unprotected samples. Some SR vesicles fuse during FT. Fusion of vesicles cannot account for the observed inactivation of the enzyme. Fluorescence studies, using intrinsic tryptophan and extrinsic FITC and NCD-4, suggest that FT does not damage the transmembrane region of the Ca2+,Mg(2+)-ATPase or the calcium binding sites, but only the mechanism coupling ATPase activity to calcium translocation. Differential scanning calorimetry (DSC) studies suggest that this region comprises less than 15% of the whole enzyme.
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Affiliation(s)
- R J Lalonde
- Department of Biology, University of Waterloo, Ontario, Canada
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21
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Sumbilla C, Cantilina T, Collins J, Malak H, Lakowicz J, Inesi G. Structural perturbation of the transmembrane region interferes with calcium binding by the Ca2+ transport ATPase. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98953-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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22
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Famulski KS, Pikula S, Wrzosek A, Wojtczak AB. The effect of Ca2+ and calmodulin on the inhibition of Ca2(+)+Mg2(+)-ATPase in erythrocyte ghost membranes by nonpolar and polar carbodiimides. Cell Calcium 1990; 11:275-80. [PMID: 2141800 DOI: 10.1016/0143-4160(90)90004-e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
N,N'-dicyclohexylcarbodiimide (DCCD) and 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide (CMCD) inhibited calmodulin-dependent Ca2(+)+Mg2(+)-ATPase activity in erythrocyte ghost membranes. The extent of the inhibition caused by carbodiimides strongly depended on their hydrophobicity. Hydrophobic DCCD was a more potent inhibitor then hydrophilic CMCD. Calmodulin (CaM) protected the enzyme against the former carbodiimide, whereas Ca2+ did the same against the latter. In contrast to previous observations made by Villalobo et al., on the purified enzyme, neither carbodiimide affected the calmodulin-independent ATPase activity in ghost membranes. Inhibition of the calmodulin-dependent ATPase activity was due to a decrease of the maximum activity, whereas the Km value for Ca2+ remained unchanged. Titration of erythrocyte ghost membranes with CaM revealed a biphasic response of ATPase to this activator. Two affinity constants were found for CaM, 0.64 nM and 14 nM. DCCD affected the interaction with CaM at high- and low-affinity binding sites in a competitive manner. CMCD acted as a noncompetitive inhibitor for CaM low-affinity sites, whereas it behaved in a competitive way against CaM interaction with high-affinity sites. In E2 form (stabilized by vanadate and EGTA) ATPase was more sensitive to carbodiimides than in E1 form (induced by La3+).
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Affiliation(s)
- K S Famulski
- Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland
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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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24
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Munkonge F, East JM, Lee AG. Positions of the sites labeled by N-cyclohexyl-N'-(4-dimethylamino-1-naphthyl)carbodiimide on the (Ca2+ + Mg2+)-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 979:113-20. [PMID: 2521797 DOI: 10.1016/0005-2736(89)90530-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
N-Cyclohexyl-N'-(4-dimethylamino-1-naphthyl)carbodiimide (NCD-4) labels (Ca2+ + Mg2+)-ATPase at Ca2+-protectable sites, believed to be at or near the two Ca2+ binding sites on the ATPase, and at nonspecific sites. The labeled ATPase has been reconstituted into lipid bilayers containing phosphatidylethanolamine labeled with fluorescein isothiocyanate. The distance between NCD-4 and fluorescein groups was measured using Forster energy transfer and the NCD-4 labels were found to be approx. 20 A from the lipid/water interface suggesting that the Ca2+ binding sites on the ATPase are also 20 A from the lipid/water interface. Addition of vanadate causes no change in the efficiency of energy transfer, suggesting that the Ca2+ binding sites on the E1 conformation of the ATPase do not move significantly with respect to the lipid/water interface in the E1-E2 transition.
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Affiliation(s)
- F Munkonge
- Department of Biochemistry, University of Southampton, U.K
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25
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Jørgensen PL, Andersen JP. Structural basis for E1-E2 conformational transitions in Na,K-pump and Ca-pump proteins. J Membr Biol 1988; 103:95-120. [PMID: 3054114 DOI: 10.1007/bf01870942] [Citation(s) in RCA: 259] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- P L Jørgensen
- Danish Biotechnology Research Center for Membrane Proteins, Aarhus University, Demark
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26
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Dicyclohexylcarbodiimide interaction with sarcoplasmic reticulum. Inhibition of Ca2+ efflux. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68788-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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27
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Villalobo A, Harris JW, Roufogalis BD. Calcium-dependent inhibition of the erythrocyte Ca2+ translocating ATPase by carbodiimides. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 858:188-94. [PMID: 2939880 DOI: 10.1016/0005-2736(86)90305-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The ATP hydrolytic activity of the solubilized and purified Ca2+-translocating ATPase from human erythrocyte plasma membrane was strongly inhibited by the nonpolar compound, N,N'-dicyclohexylcarbodiimide, both in the presence and in the absence of calmodulin. However, the more water-soluble carbodiimides, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide had little inhibitory effect on the enzyme. The inhibitory effect of N,N'-dicyclohexylcarbodiimide was most pronounced at acid pH, and declined sharply at alkaline pH values. In addition, the optimum pH for the enzyme activity also shifted to more alkaline values in the presence of the carbodiimide. Calcium ion appears to favor the inhibition induced by the carbodiimide, in contrast to the observed protection by Ca2+ in the sarcoplasmic reticulum Ca2+-translocating ATPase. N,N'-Dicyclohexylcarbodiimide also dramatically decreased the stimulatory effect of calmodulin on the activity of the enzyme.
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Nałecz MJ, Casey RP, Azzi A. Use of N,N'-dicyclohexylcarbodiimide to study membrane-bound enzymes. Methods Enzymol 1986; 125:86-108. [PMID: 2872577 DOI: 10.1016/s0076-6879(86)25009-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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29
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Pick U, Weiss M. Spectral and catalytical properties of the sarcoplasmic reticulum Ca-ATPase labeled with N-cyclohexyl-N'-(4-dimethylamino-1-naphthyl)-carbodiimide. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 152:83-9. [PMID: 2931277 DOI: 10.1111/j.1432-1033.1985.tb09166.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
N-Cyclohexyl-N'-(dimethylamino)-carbodiimide (NCD-4) labels three sites in the sarcoplasmic reticulum Ca-ATPase which can be resolved by their spectral properties and by their effects on the catalytical activity of the enzyme. One site is not protectable by Ca2+ ions or by dicyclohexylcarbodiimide and is not essential for catalytical activity. Two Ca2+-protectable sites, whose modification leads to a biphasic inhibition of Ca-ATPase activity, have fluorescence emission maxima at 407 nm and 425 nm. The Ca-ATPase modified by NCD-4 hydrolyses ATP but does not translocate Ca2+ nor does it undergo the conformational changes associated with Ca2+ binding in the native enzyme. High concentrations of Ca2+ induce slow biphasic fluorescence quenching in the Ca-ATPase labeled selectively at the 407-nm site but the signals are largely abolished by modification of the 425-nm site. Both vanadate ions and ATP reverse this Ca2+-induced fluorescence quenching. It is proposed that NCD-4 labels the two high-affinity Ca2+-binding sites of the Sarcoplasmic reticulum Ca-ATPase and that the conformational changes in the modified enzyme may reflect interactions between the two sites.
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Chadwick CC, Thomas EW. Inhibition of (Ca2+ + Mg2+)-ATPase by carbodiimides. A structure-activity study. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 827:419-23. [PMID: 3155970 DOI: 10.1016/0167-4838(85)90227-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Nine hydrophobic carbodiimides were synthesized and their chemical reactivities (towards acetic acid) and inhibitory capacities (towards the (Ca2+ + Mg2+)-ATPase were measured. No correlation between chemical reactivity and inhibitory efficacy emerges, but a significant effect of molecular bulk on reactivity towards the calcium-protectable carboxyl groups of the ATPase is noted: methyl-substituted compounds inhibit the enzyme in the presence of Ca2+, while aryl- or cyclohexyl-substituted compounds do not inactivate in the presence of Ca2+.
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31
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Azzi A, Casey RP, Nałecz MJ. The effect of N,N'-dicyclohexylcarbodiimide on enzymes of bioenergetic relevance. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 768:209-26. [PMID: 6095905 DOI: 10.1016/0304-4173(84)90017-x] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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32
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Chadwick CC, Thomas EW. Ligand binding properties of the sarcoplasmic reticulum (Ca2+ + Mg2+)-ATPase labelled with N-cyclohexyl-N'-(4-dimethylamino-alpha-naphthyl)carbodiimide. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 769:291-6. [PMID: 6141803 DOI: 10.1016/0005-2736(84)90309-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The (Ca2+ + Mg2+)-ATPase of rabbit sarcoplasmic reticulum, when labelled at two Ca2+-protected sites with N-cyclohexyl-N'-(4-dimethylamino-alpha-naphthyl)carbodiimide (NCD-4) retains Ca2+ binding capacity at the sites with Kd values of approx. 3 microM and 0.12 mM as assessed by fluorescence titration. The sites correspond to the two high-affinity Ca2+ binding sites present in the native ATPase. The NCD-4 labelled ATPase exhibits slow conformational changes at each site on addition of Ca2+. It retains the ability to form phosphoenzyme, and can most likely translocate Ca2+.
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