Sugar binding induced charge translocation in the melibiose permease from Escherichia coli.


:Electrogenic events associated with the activity of the melibiose permease (MelB), a transporter from Escherichia coli, were investigated. Proteoliposomes containing purified MelB were adsorbed to a solid supported lipid membrane, activated by a substrate concentration jump, and transient currents were measured. When the transporter was preincubated with Na(+) at saturating concentrations, a charge translocation in the protein upon melibiose binding could still be observed. This result demonstrates that binding of the uncharged substrate melibiose triggers a charge displacement in the protein. Further analysis showed that the charge displacement is neither related to extra Na(+) binding to the transporter, nor to the displacement of already bound Na(+) within the transporter. The electrogenic melibiose binding process is explained by a conformational change with concomitant displacement of charged amino acid side chains and/or a reorientation of helix dipoles. A kinetic model is suggested, in which Na(+) and melibiose binding are distinct electrogenic processes associated with approximately the same charge displacement. These binding reactions are fast in the presence of the respective cosubstrate (k > 50 s(-1)).






Meyer-Lipp K,Ganea C,Pourcher T,Leblanc G,Fendler K




Has Abstract


2004-10-05 00:00:00












  • Formation of a copper specific binding site in non-native states of beta-2-microglobulin.

    abstract::A debilitating complication of long-term hemodialysis is the deposition of beta-2-microglobulin (beta2m) as amyloid plaques in the joint space. We have recently shown that Cu(2+) can be a contributing, if not causal, factor at concentrations encountered during dialysis therapy. The basis for this effect is destabiliza...


    pub_type: 杂志文章


    authors: Eakin CM,Knight JD,Morgan CJ,Gelfand MA,Miranker AD

    更新日期:2002-08-27 00:00:00

  • The effect of Mn2+ and Co2+ on the activities of a zinc metallodipeptidase from a mouse ascites tumor.

    abstract::Kinetic studies of the effect of addition of Co2+ or Mn2+ to a highly purified dipeptidase from Ehrlich-Lettré mouse ascites tumor cells show that these metals specifically activate the hydrolyses of certain classes of dipeptides. This enzyme was previously (S. Hayman and E. K. Patterson, 1971, J. Biol. Chem. 246, 660...


    pub_type: 杂志文章


    authors: Patterson EK,Gatmaitan JS,Hayman S

    更新日期:1975-09-23 00:00:00

  • Identification of the cyclosporin-binding site in P-glycoprotein.

    abstract::The binding site of cyclosporin A to P-glycoprotein was characterized by using a multidrug-resistant Chinese hamster ovary cell line. P-glycoprotein photolabeled with diazirine-cyclosporin A analogue was purified by a two-step process involving continuous elution electrophoresis followed by wheat germ agglutinin-agaro...


    pub_type: 杂志文章


    authors: Demeule M,Laplante A,Murphy GF,Wenger RM,Béliveau R

    更新日期:1998-12-22 00:00:00

  • Metal ion activator effects on intrinsic isotope effects for hydride transfer from decarboxylation in the reaction catalyzed by the NAD-malic enzyme from Ascaris suum.

    abstract::The mechanism of the oxidative decarboxylation reaction catalyzed by the NAD-malic enzyme from Ascaris suum has been examined with several different divalent metal ion activators and dinucleotide substrates. Primary deuterium and tritium isotope effects have been obtained and, in combination with the partitioning rati...


    pub_type: 杂志文章


    authors: Karsten WE,Gavva SR,Park SH,Cook PF

    更新日期:1995-03-14 00:00:00

  • Dissection of porphyrin-induced conformational dynamics in the heme biosynthesis enzyme ferrochelatase.

    abstract::Human ferrochelatase (EC catalyzes the insertion ferrous iron into protoporphyrin IX as the last step in heme biosynthesis, an essential process to most organisms given the vast intracellular functions of heme. Even with multiple ferrochelatase structures available, the exact mechanism for iron insertion int...


    pub_type: 杂志文章


    authors: Asuru AP,An M,Busenlehner LS

    更新日期:2012-09-11 00:00:00

  • Inhibitors can activate proteases to catalyze the synthesis and hydrolysis of peptides.

    abstract::Competitive inhibitors can activate proteases (papain, trypsin, and cathepsin S) to catalyze the synthesis of peptide bonds and accelerate the hydrolysis of poor substrates (from 1 to 99%). Reaction mixtures contained intermediate molecules that were formed by the coupling of the inhibitor with the poor substrate. Thi...


    pub_type: 杂志文章


    authors: Schechter I,Ziv E

    更新日期:2006-12-12 00:00:00

  • Membrane topography of the photosynthetic reaction center polypeptides of Rhodopseudomonas sphaeroides.

    abstract::The topography of the photosynthetic reaction center (RC) polypeptides (H, M, and L) was investigated by proteolysis and radioiodination of membrane vesicles isolated from Rhodopseudomonas sphaeroides. Chromatophores, obtained from French-pressed cell lysates, are closed vesicles' and oriented inside out with respect ...


    pub_type: 杂志文章


    authors: Bachmann RC,Gillies K,Takemoto JY

    更新日期:1981-08-04 00:00:00

  • Secondary structure of human interleukin 2 from 3D heteronuclear NMR experiments.

    abstract::Recombinant 15N-labeled human interleukin 2 (IL-2) has been studied by 2D and 3D NMR using uniformly 15N-labeled protein. Assignment of the backbone resonances has enabled the secondary structure of the protein to be defined. The secondary structure was found to consist of four alpha-helical regions and a short sectio...


    pub_type: 杂志文章


    authors: Mott HR,Driscoll PC,Boyd J,Cooke RM,Weir MP,Campbell ID

    更新日期:1992-08-25 00:00:00

  • A bacterially expressed mineralocorticoid receptor is associated in vitro with the 90-kilodalton heat shock protein and shows typical hormone- and DNA-binding characteristics.

    abstract::A recombinant system was developed for generation of steroid-receptor complexes in vitro. The DNA- and steroid-binding domains of the rat mineralocorticoid receptor were expressed in Escherichia coli as a fusion protein with glutathione S-transferase. The identity of the expressed recombinant protein was confirmed by ...


    pub_type: 杂志文章


    authors: Caamaño CA,Morano MI,Patel PD,Watson SJ,Akil H

    更新日期:1993-08-24 00:00:00

  • Sequential degradation of alphaII and betaII spectrin by calpain in glutamate or maitotoxin-stimulated cells.

    abstract::Calpain-catalyzed proteolysis of II-spectrin is a regulated event associated with neuronal long-term potentiation, platelet and leukocyte activation, and other processes. Calpain proteolysis is also linked to apoptotic and nonapoptotic cell death following excessive glutamate exposure, hypoxia, HIV-gp120/160 exposure,...


    pub_type: 杂志文章


    authors: Glantz SB,Cianci CD,Iyer R,Pradhan D,Wang KK,Morrow JS

    更新日期:2007-01-16 00:00:00

  • Chromatin structural changes in synchronized cells blocked in early S phase by sequential use of isoleucine deprivation and hydroxyurea blockade.

    abstract::We have investigated the loss of histone H1 from chromatin [D'Anna, J. A., Gurley, L. R., & Tobey, R. A. (1982) Biochemistry 21, 3991-4001] and the structure of chromatin from Chinese hamster (line CHO) cells blocked in early S phase by sequential use of isoleucine deprivation G1 block and 1 mM hydroxyurea (HU) blocka...


    pub_type: 杂志文章


    authors: D'Anna JA,Prentice DA

    更新日期:1983-11-22 00:00:00

  • Role of zinc ions in activation and inactivation of thrombin-activatable fibrinolysis inhibitor.

    abstract::Thrombin-activatable fibrinolysis inhibitor (TAFI) circulates as an inactive proenzyme of a carboxypeptidase B-like enzyme (TAFIa). It functions by removing C-terminal lysine residues from partially degraded fibrin that are important in tissue-type plasminogen activator mediated plasmin formation. TAFI was classified ...


    pub_type: 杂志文章


    authors: Marx PF,Bouma BN,Meijers JC

    更新日期:2002-01-29 00:00:00

  • Decrease in ADP-ribosylation of HeLa non-histone proteins from interphase to metaphase.

    abstract::Variations for non-histones in the ADP-ribosylating activities of interphase and metaphase cells were investigated. 32P-Labeled nicotinamide adenine dinucleotide ([32P]NAD), the specific precursor for the modification, was used to radioactively label proteins. Permeabilized interphase and mitotic cells, as well as iso...


    pub_type: 杂志文章


    authors: Adolph KW,Song MK

    更新日期:1985-01-15 00:00:00

  • The polar nature of 7-ketocholesterol determines its location within membrane domains and the kinetics of membrane microsolubilization by apolipoprotein A-I.

    abstract::7-Ketocholesterol is an oxidized derivative of cholesterol with numerous physiological effects. In model membranes, 7-ketocholesterol and cholesterol were compared by physical measures of bilayer order and polarity, formation of detergent resistant domains (DRM), phase separation, and membrane microsolubilization by a...


    pub_type: 杂志文章


    authors: Massey JB,Pownall HJ

    更新日期:2005-08-02 00:00:00

  • The arginine finger loop of yeast and human GAP is a determinant for the specificity toward Ras GTPase.

    abstract::In this work, we have studied the role of the arginine finger region in determining the specificity of the GTPase activating proteins (GAPs) Saccharomyces cerevisiae Ira2p and human p120-GAP toward yeast Ras2p and human Ha-Ras p21. It is known that p120-GAP can enhance both Ras2p and Ha-Ras GTPase activities, whereas ...


    pub_type: 杂志文章


    authors: te Biesebeke R,Krab IM,Parmeggiani A

    更新日期:2001-06-26 00:00:00

  • Topological effects of the TATA box binding protein on minicircle DNA and a possible thermodynamic linkage to chromatin remodeling.

    abstract::DNA ring closure experiments on short restriction fragments ( approximately 160 bp) bound by the TATA box binding protein (TBP) have demonstrated the formation of negative topoisomers, consistent with crystallographically observed TBP-induced DNA untwisting but in contrast to most previous results on topological effec...


    pub_type: 杂志文章,评审


    authors: Kahn JD

    更新日期:2000-04-04 00:00:00

  • Comparison of lipid/gramicidin dispersions and cocrystals by Raman scattering.

    abstract::Gramicidin crystals, dimyristoylphosphatidylcholine (DMPC)/gramicidin dispersions, and DMPC/gramicidin cocrystals were examined by Raman scattering to determine lipid/gramicidin stoichiometries and lipid organization. Calibrations of the choline (716-cm-1) and tryptophan (756-cm-1) peaks indicate that the cocrystals c...


    pub_type: 杂志文章


    authors: Short KW,Wallace BA,Myers RA,Fodor SP,Dunker AK

    更新日期:1987-01-27 00:00:00

  • The nickel site of Bacillus pasteurii UreE, a urease metallo-chaperone, as revealed by metal-binding studies and X-ray absorption spectroscopy.

    abstract::UreE is a homodimeric metallo-chaperone that assists the insertion of Ni(2+) ions in the active site of urease. The crystal structures of UreE from Bacillus pasteurii and Klebsiella aerogenes have been determined, but the details of the nickel-binding site were not elucidated due to solid-state effects that caused dis...


    pub_type: 杂志文章


    authors: Stola M,Musiani F,Mangani S,Turano P,Safarov N,Zambelli B,Ciurli S

    更新日期:2006-05-23 00:00:00

  • The R163K mutant of human thymidylate synthase is stabilized in an active conformation: structural asymmetry and reactivity of cysteine 195.

    abstract::Loop 181-197 of human thymidylate synthase (hTS) populates two conformational states. In the first state, Cys195, a residue crucial for catalytic activity, is in the active site (active conformer); in the other conformation, it is about 10 A away, outside the active site (inactive conformer). We have designed and expr...


    pub_type: 杂志文章


    authors: Gibson LM,Lovelace LL,Lebioda L

    更新日期:2008-04-22 00:00:00

  • Mycoplasma gallisepticum produces a histone-like protein that recognizes base mismatches in DNA.

    abstract::Mycoplasmas are the smallest known microorganisms, with drastically reduced genome sizes. One of the essential biochemical pathways lost in mycoplasmas is methylation-mediated DNA repair (MMR), which is responsible for correction of base substitutions, insertions, and deletions in both bacteria and higher organisms. W...


    pub_type: 杂志文章


    authors: Kamashev D,Oberto J,Serebryakova M,Gorbachev A,Zhukova Y,Levitskii S,Mazur AK,Govorun V

    更新日期:2011-10-11 00:00:00

  • Role of a heterogeneous free state in the formation of a specific RNA-theophylline complex.

    abstract::The helical regions of RNA are generally very stable, but the single-stranded and loop regions often exist as an ensemble of conformations in solution. The theophylline-binding RNA aptamer forms a very stable structure when bound to the bronchodilator theophylline, but the theophylline binding site is not stably forme...


    pub_type: 杂志文章


    authors: Jucker FM,Phillips RM,McCallum SA,Pardi A

    更新日期:2003-03-11 00:00:00

  • On the mechanism of activation of the BLUF domain of AppA.

    abstract::AppA, a transcriptional antirepressor, regulates the steady expression of photosynthesis genes in Rhodobacter sphaeroides in response to high-intensity blue light and to redox signals. Its blue-light sensing is mediated by an N-terminal BLUF domain, a member of a novel flavin fold. The photocycle of this domain (AppA(...


    pub_type: 杂志文章


    authors: Laan W,Gauden M,Yeremenko S,van Grondelle R,Kennis JT,Hellingwerf KJ

    更新日期:2006-01-10 00:00:00

  • Analysis of substrate-induced electronic, catalytic, and structural changes in inducible NO synthase.

    abstract::Inducible nitric oxide synthase (iNOS) catalyzes the NADPH-dependent formation of nitric oxide (NO) and citrulline from L-arginine and O2. In addition to serving as substrate, L-arginine alters the enzyme's heme iron spin equilibrium, increases its NADPH oxidation, and promotes assembly of active dimeric iNOS from ina...


    pub_type: 杂志文章


    authors: Sennequier N,Stuehr DJ

    更新日期:1996-05-07 00:00:00

  • Metal ion-induced stabilization and refolding of anticoagulation factor II from the venom of Agkistrodon acutus.

    abstract::Anticoagulation factor II (ACF II) isolated from the venom of Agkistrodon acutus is an activated coagulation factor X-binding protein in a Ca(2+)-dependent fashion with marked anticoagulant activity. The equilibrium unfolding/refolding of apo-ACF II, holo-ACF II, and Tb(3+)-reconstituted ACF II in guanidine hydrochlor...


    pub_type: 杂志文章


    authors: Xu X,Liu Q,Xie Y

    更新日期:2002-03-19 00:00:00

  • The thermodynamic and structural differences among the catalytically active complexes of phosphoglucomutase: metal ion effects.

    abstract::When the identity of the metal ion activator, M, is changed within the series, Zn2+, Co2+, Mg2+, Ni2+, Mn2+, and Cd2+, the equilibrium distribution among the central complexes in the phosphoglucomutase system is markedly altered. (The central complexes are Ep-M-Glc-6-P, ED-M-Glc-1,6-P2, and Ep-M-Glc-1-P, where Ep and ...


    pub_type: 杂志文章


    authors: Ray WJ Jr,Long JW

    更新日期:1976-09-07 00:00:00

  • Structure of isocitrate dehydrogenase with isocitrate, nicotinamide adenine dinucleotide phosphate, and calcium at 2.5-A resolution: a pseudo-Michaelis ternary complex.

    abstract::The structure of isocitrate dehydrogenase (IDH) with a bound complex of isocitrate, NADP+, and Ca2+ was solved at 2.5-A resolution and compared by difference mapping against previously determined enzymatic complexes. Calcium replaces magnesium in the binding of metal-substrate chelate complex, resulting in a substanti...


    pub_type: 杂志文章


    authors: Stoddard BL,Dean A,Koshland DE Jr

    更新日期:1993-09-14 00:00:00

  • Activation-induced subcellular redistribution of G alpha(s) is dependent upon its unique N-terminus.

    abstract::The heterotrimeric G protein subunit, alpha(s), can move reversibly from plasma membranes to cytoplasm in response to activation by GPCRs or activating mutations. We examined the importance of the unique N-terminus of alpha(s) in this translocation in cultured cells. alpha(s) contains a single site for palmitoylation ...


    pub_type: 杂志文章


    authors: Thiyagarajan MM,Bigras E,Van Tol HH,Hébert TE,Evanko DS,Wedegaertner PB

    更新日期:2002-07-30 00:00:00

  • Chromatin assembly factor 1 interacts with histone H3 methylated at lysine 79 in the processes of epigenetic silencing and DNA repair.

    abstract::In eukaryotic cells, chromatin is classified into euchromatin, which is active in transcription, and heterochromatin that silences transcription. Histones in these two domains contain distinct modifications. Chromatin assembly factor 1 (CAF-1) is a highly conserved protein that functions in DNA replication, DNA repair...


    pub_type: 杂志文章


    authors: Zhou H,Madden BJ,Muddiman DC,Zhang Z

    更新日期:2006-03-07 00:00:00

  • Effects of nucleotide- and aurodox-induced changes in elongation factor Tu conformation upon its interactions with aminoacyl transfer RNA. A fluorescence study.

    abstract::The effects of GDP and of aurodox (N-methylkirromycin) on the affinity of elongation factor Tu (EF-Tu) for aminoacyl-tRNA (aa-tRNA) have been quantified spectroscopically by using Phe-tRNA(Phe)-Fl8, a functionally active analogue of Phe-tRNA(Phe) with a fluorescein dye convalently attached to the s4U-8 base. The assoc...


    pub_type: 杂志文章


    authors: Dell VA,Miller DL,Johnson AE

    更新日期:1990-02-20 00:00:00

  • Explanation of pre-steady-state kinetics and decreased burst amplitude of HIV-1 reverse transcriptase at sites of modified DNA bases with an additional, nonproductive enzyme-DNA-nucleotide complex.

    abstract::The majority of pre-steady-state kinetic investigations with HIV-1 reverse transcriptase (HIV-1 RT) have reported substoichiometric bursts (30-50%) of product formation in the initial reaction cycle. By using quantitative amino acid analysis, we have revised the extinction coefficient of the HIV-1 RT heterodimer and s...


    pub_type: 杂志文章


    authors: Furge LL,Guengerich FP

    更新日期:1999-04-13 00:00:00