Aluminum exchange between citrate and human serum transferrin and interaction with transferrin receptor 1.


:The kinetics and thermodynamics of Al(III) exchange between aluminum citrate (AlL) and human serum transferrin were investigated in the 7.2-8.9 pH range. The C-site of human serum apotransferrin in interaction with bicarbonate removes Al(III) from Al citrate with an exchange equilibrium constant K1 = (2.0 +/- 0.6) x 10(-2); a direct second-order rate constant k1 = 45 +/- 3 M(-1) x s(-1); and a reverse second-order rate constant k(-1) = (2.3 +/- 0.5) x 10(3) M(-1) x s(-1). The newly formed aluminum-protein complex loses a single proton with proton dissociation constant K1a = (15 +/- 3) nM to yield a first kinetic intermediate. This intermediate then undergoes a modification in its conformation followed by two proton losses; first-order rate constant k2 = (4.20 +/- 0.02) x 10(-2) s(-1) to produce a second kinetic intermediate, which in turn undergoes a last slow modification in the conformation to yield the aluminum-loaded transferrin in its final state. This last process rate-controls Al(III) uptake by the N-site of the protein and is independent of the experimental parameters with a constant reciprocal relaxation time tau3(-1) = (6 +/- 1) x 10(-5) x s(-1). The affinities involved in aluminum uptake by serum transferrins are about 10 orders of magnitude lower than those involved in the uptake of iron. The interactions of iron-loaded transferrins with transferrin receptor 1 occur with average dissociation constants of 3 +/- 1 and 5 +/- 1 nM for the only C-site iron-loaded and of 6.0 +/- 0.6 and 7 +/- 0.5 nM for the iron-saturated ST in the absence or presence of CHAPS, respectively. No interaction is detected between receptor 1 and aluminum-saturated or mixed C-site iron-loaded/N-site aluminum-loaded transferrin under the same conditions. The fact that aluminum can be solubilized by serum transferrin in biological fluids does not necessarily imply that its transfer from the blood stream to cytoplasm follows the receptor-mediated pathway of iron transport by transferrins.






Hémadi M,Miquel G,Kahn PH,El Hage Chahine JM




Has Abstract


2003-03-18 00:00:00












  • Guanidine hydrochloride induced unfolding of the alpha subunit of tryptophan synthase and of the two alpha proteolytic fragments: evidence for stepwise unfolding of the two alpha domains.

    abstract::The relationship between the domain structure of the alpha subunit of Escherichia coli tryptophan synthase and the mechanism of unfolding of the alpha subunit is investigated. Previous studies of the unfolding of the alpha subunit by increasing concentrations of guanidine hydrochloride or urea detected a partially unf...


    pub_type: 杂志文章


    authors: Miles EW,Yutani K,Ogasahara K

    更新日期:1982-05-25 00:00:00

  • Details of mannitol transport in Escherichia coli elucidated by site-specific mutagenesis and complementation of phosphorylation site mutants of the phosphoenolpyruvate-dependent mannitol-specific phosphotransferase system.

    abstract::The mannitol transport protein (EIImtl) carries out translocation with concomitant phosphorylation of mannitol from the periplasm to the cytoplasm, at the expense of phosphoenolpyruvate (PEP). The phosphoryl group which is needed for this group translocation is sequentially transferred from PEP via two phosphorylation...


    pub_type: 杂志文章


    authors: van Weeghel RP,van der Hoek YY,Pas HH,Elferink M,Keck W,Robillard GT

    更新日期:1991-02-19 00:00:00

  • Structure of the type III pantothenate kinase from Bacillus anthracis at 2.0 A resolution: implications for coenzyme A-dependent redox biology.

    abstract::Coenzyme A (CoASH) is the major low-molecular weight thiol in Staphylococcus aureus and a number of other bacteria; the crystal structure of the S. aureus coenzyme A-disulfide reductase (CoADR), which maintains the reduced intracellular state of CoASH, has recently been reported [Mallett, T.C., Wallen, J.R., Karplus, ...


    pub_type: 杂志文章


    authors: Nicely NI,Parsonage D,Paige C,Newton GL,Fahey RC,Leonardi R,Jackowski S,Mallett TC,Claiborne A

    更新日期:2007-03-20 00:00:00

  • Protection of satellite tobacco necrosis virus ribonucleic acid by wheat germ 40S and 80S ribosomes.

    abstract::Wheat germ ribosomes combine with the AUG codon at positions 30-32 from the 5' terminus of in vitro radioiodinated satellite tobacco necrosis virus (STNV) ribonucleic acid (RNA) to form initiation complexes that protect specific regions of the RNA from attack by ribonucleases. Wheat gern 80S ribosomes convey partial p...


    pub_type: 杂志文章


    authors: Browning KS,Leung DW,Clark JM Jr

    更新日期:1980-05-13 00:00:00

  • Natural mutagenesis study of the human steroid 5 alpha-reductase 2 isozyme.

    abstract::The enzyme steroid 5 alpha-reductase utilizes NADPH to reduce the double bonds of a variety of steroid substrates with generalized 3-oxo, delta 4,5 structures. One substrate for this membrane-bound enzyme is testosterone, whose reduction to dihydrotestosterone is required for the embryonic differentiation of the exter...


    pub_type: 杂志文章


    authors: Wigley WC,Prihoda JS,Mowszowicz I,Mendonca BB,New MI,Wilson JD,Russell DW

    更新日期:1994-02-08 00:00:00

  • A Biochemical Lanthanide-Encoding Approach Enables Quantitative Monitoring of the Bacterial Response to Vancomycin Treatment.

    abstract::A pathogenic bacterium has its own mechanisms for not only pathogenic attack but also exogenous invasion defense, in which the bacterial cell wall is the front line of attack and defense. We developed a biochemical lanthanide-encoding approach to quantify the uncanonical d-amino acid (d-X) that was edited in a small p...


    pub_type: 杂志文章


    authors: Zhao W,Liang Y,Yan X,Yang L,Wang Q

    更新日期:2020-09-29 00:00:00

  • A Novel Soluble Peptide with pH-Responsive Membrane Insertion.

    abstract::Several diseases, such as cancer, are characterized by acidification of the extracellular environment. Acidosis can be employed as a target to specifically direct therapies to the diseased tissue. We have used first principles to design an acidity-triggered rational membrane (ATRAM) peptide with high solubility in sol...


    pub_type: 杂志文章


    authors: Nguyen VP,Alves DS,Scott HL,Davis FL,Barrera FN

    更新日期:2015-11-03 00:00:00

  • Site specific combinations of stabilizing and destabilizing amino acid replacements in yeast cytochrome c: in vivo and in vitro effects.

    abstract::Oligonucleotide-directed mutagenesis in vivo was used to create destabilizing site specific changes at position 6 in iso-1-cytochrome c in Saccharomyces cerevisiae. These changes were made in combination with the stabilizing N52I substitution. The resulting proteins showed that a variety of forces and interactions are...


    pub_type: 杂志文章


    authors: Linske-O'Connell LI,Sherman F,McLendon G

    更新日期:1995-05-30 00:00:00

  • Effects of exposure to low pH on the lateral mobility of influenza hemagglutinin expressed at the cell surface: correlation between mobility inhibition and inactivation.

    abstract::To investigate the possible role of viral glycoprotein mobility in membrane fusion, fluorescence photobleaching recovery was employed to study the effects of exposure to mildly acidic pH (required to convert many viral fusion proteins to the fusion-active form) on the lateral mobility of influenza hemagglutinin (HA) p...


    pub_type: 杂志文章


    authors: Gutman O,Danieli T,White JM,Henis YI

    更新日期:1993-01-12 00:00:00

  • DNA binding properties and replication activity of the T antigen related D2 phosphoprotein.

    abstract::According to earlier genetic experiments, a region within the N-terminal 50-100 amino acids may be important for the replication function of T antigen, the initiator protein of simian virus 40 (SV40). We have investigated this possibility using the T antigen related D2 protein in several biochemical assay systems. D2 ...


    pub_type: 杂志文章


    authors: Klausing K,Scheffner M,Scheidtmann KH,Stahl H,Knippers R

    更新日期:1989-03-07 00:00:00

  • Nucleation of actin polymerization by villin and elongation at subcritical monomer concentration.

    abstract::We have obtained a quantitative description of villin-nucleated actin polymerization in physiological salt by determining the concentrations of free villin (V), villin-actin monomer (VA), villin-actin dimer (VA2), and villin-actin oligomer (VAn). Over a range of actin-villin ratios from 0.1 to 20 we determined the con...


    pub_type: 杂志文章


    authors: Weber A,Northrop J,Bishop MF,Ferrone FA,Mooseker MS

    更新日期:1987-05-05 00:00:00

  • Steps toward constructing a cytochrome b6 f complex in the purple bacterium Rhodobacter sphaeroides: an example of the structural plasticity of a membrane cytochrome.

    abstract::We have modified the cytochrome b subunit of the cytochrome bc1 complex from the purple bacterium Rhodobacter sphaeroides to introduce two distinctive features of cytochrome b6 f complexes. In the first one, we have split cyt b into two polypeptides thus mimicking the organization of cyt b6 and subunit IV in the b6 f ...


    pub_type: 杂志文章


    authors: Kuras R,Guergova-Kuras M,Crofts AR

    更新日期:1998-11-17 00:00:00

  • A new mechanism for repairing oxidative damage to DNA: (A)BC excinuclease removes AP sites and thymine glycols from DNA.

    abstract::Escherichia coli (A)BC excinuclease is the major enzyme responsible for removing bulky adducts, such as pyrimidine dimers and 6-4 photoproducts, from DNA. Mutants deficient in this enzyme are extremely sensitive to UV and UV-mimetic agents, but not to oxidizing agents, or ionizing radiation which damages DNA in part b...


    pub_type: 杂志文章


    authors: Lin JJ,Sancar A

    更新日期:1989-10-03 00:00:00

  • Modifying the substrate specificity of staphylococcal lipases.

    abstract::The lipase from Staphylococcus hyicus (SHL) displays a high phospholipase activity whereas the homologous S. aureus lipase (SAL) is not active or hardly active on phospholipid substrates. Previously, it has been shown that elements within the region comprising residues 254-358 are essential for the recognition of phos...


    pub_type: 杂志文章


    authors: van Kampen MD,Verheij HM,Egmond MR

    更新日期:1999-07-20 00:00:00

  • Ligand interactions in the distal heme pocket of Mycobacterium tuberculosis truncated hemoglobin N: roles of TyrB10 and GlnE11 residues.

    abstract::The crystallographic structure of oxygenated trHbN from Mycobacterium tuberculosis showed an extended heme distal site hydrogen-bonding network that includes Y(B10), Q(E11), and the bound O(2) (Milani, M., et al. (2001) EMBO J. 20, 3902-3909). In the present work, we analyze the effects that substitutions at the B10 a...


    pub_type: 杂志文章


    authors: Ouellet Y,Milani M,Couture M,Bolognesi M,Guertin M

    更新日期:2006-07-25 00:00:00

  • Donor-acceptor distance distributions in a double-labeled fluorescent oligonucleotide both as a single strand and in duplexes.

    abstract::A 16-mer deoxyribonucleotide was labeled at the 5'-end with x-rhodamine and at the 3'-end with fluorescein. Förster resonance energy transfer was used to determine the distribution, P(R), of donor-acceptor distances for the oligomer in three duplex structures (hybridized to complementary strands having 10, 16, and 24 ...


    pub_type: 杂志文章


    authors: Parkhurst KM,Parkhurst LJ

    更新日期:1995-01-10 00:00:00

  • Product dependence of deuterium isotope effects in enzyme-catalyzed reactions.

    abstract::Theory for enzyme-catalyzed reactions is developed for the dependence on product concentration of deuterium isotope effects on V and V/K. Generally, a product that decreases the off-rate for a second product to zero causes the isotope effect on V/K to decrease to DKeq and that on V to decrease to a value between 1 and...


    pub_type: 杂志文章


    authors: Cook PF,Yoon MY,Hara S,McClure GD Jr

    更新日期:1993-02-23 00:00:00

  • Neuronal Synapses: Microscale Signal Processing Machineries Formed by Phase Separation?

    abstract::The organization principles underlying non-membrane-bound organelles have started to unravel in the past 10 years. A new biophysical model known as biomolecular condensates has been proposed to explain many aspects of membraneless organelle assembly and regulation. Neurons are extremely complex, and each neuron can co...


    pub_type: 杂志文章,评审


    authors: Feng Z,Zeng M,Chen X,Zhang M

    更新日期:2018-05-01 00:00:00

  • Characterization of interactions between a two-component response regulator, Spo0F, and its phosphatase, RapB.

    abstract::The phosphorelay signal transduction pathway controls sporulation initiation in Bacillus subtilis. Transfer of a phosphoryl group from multiple kinases (KinA and KinB) through a single domain response regulator homologue (Spo0F), a phosphotransferase (Spo0B), and ultimately to a transcriptional regulator, (Spo0A) acti...


    pub_type: 杂志文章


    authors: Tzeng YL,Feher VA,Cavanagh J,Perego M,Hoch JA

    更新日期:1998-11-24 00:00:00

  • Recombinant human CNTF receptor alpha: production, binding stoichiometry, and characterization of its activity as a diffusible factor.

    abstract::The primary ligand-binding protein (CNTFR alpha) of the multicomponent receptor for ciliary neurotrophic factor was produced in Escherichia coli. Using novel applications of size-exclusion chromatography and a protein gel-shift assay, we obtained quantitative separation of correctly refolded protein, as well as analyt...


    pub_type: 杂志文章


    authors: Panayotatos N,Everdeen D,Liten A,Somogyi R,Acheson A

    更新日期:1994-05-17 00:00:00

  • Acid-base properties of ionophore A23187 in methanol-water solutions and bound to unilamellar vesicles of dimyristoylphosphatidylcholine.

    abstract::The acid-base properties of ionophore A23187 in methanol-water solutions (0--95% w/w) and bound to unilamellar vesicles of dimyristoylphosphatidylcholine were examined by ultraviolet and fluorescence spectroscopy, and the spectral properties for the acidic and basic forms were defined under these conditions. Standard ...


    pub_type: 杂志文章


    authors: Kauffman RF,Taylor RW,Pfeiffer DR

    更新日期:1982-05-11 00:00:00

  • Isolation and characterization of neutralizing single-chain antibodies against Xenopus mitogen-activated protein kinase kinase from phage display libraries.

    abstract::MAP kinase kinase (MAPKK) is a dual specificity protein kinase that phosphorylates and activates MAP kinase in vivo. In this study, four mouse monoclonal single-chain Fv (scFv) antibodies (Y1-6, Y1-7, Y3-6, and Y3-11) that can specifically bind to Xenopus MAPKK were isolated from combinatorial scFv-displaying phage li...


    pub_type: 杂志文章


    authors: Kosako H,Akamatsu Y,Tsurushita N,Lee KK,Gotoh Y,Nishida E

    更新日期:1996-10-08 00:00:00

  • Nearest neighbor analysis of the SecYEG complex. 2. Identification of a SecY-SecE cytosolic interface.

    abstract::Although the importance of interactions involving both the cytosolic and transmembrane regions of SecY and SecE has been documented, no information has been available for the physical contact sites of these translocase subunits in their cytosolic domains. We now carried out site-specific cross-linking experiments to i...


    pub_type: 杂志文章


    authors: Satoh Y,Mori H,Ito K

    更新日期:2003-06-24 00:00:00

  • Generation of a free alpha-amino group by Raney nickel after 2-nitro-5-thiocyanobenzoic acid cleavage at cysteine residues: application to automated sequencing.

    abstract::The selective reaction of SH containing proteins and peptides with NTCB (2-nitro-5-thiocyanobenzoic acid) has been reported (Degani, Y., & Patchornick, A. (1974) Biochemistry 13, 1; Jacobson, G.A., Schaffer, M.H., Stark, G.R., & Vanaman, T.C. (1973) J. Biol. Chem. 248, 6583). With this reagent, cysteinyl peptide bonds...


    pub_type: 杂志文章


    authors: Otieno S

    更新日期:1978-12-12 00:00:00

  • Identification of the six ligands to manganese(II) in transition-state-analogue complexes of creatine kinase: oxygen-17 superhyperfine coupling from selectively labeled ligands.

    abstract::The complete coordination scheme for Mn(II) in transition-state-analogue complexes with creatine kinase has been determined by electron paramagnetic resonance (EPR) spectroscopy. Perturbations in the EPR spectra for Mn(II) due to superhyperfine coupling to 17O of selectively labeled ligands have been used to identify ...


    pub_type: 杂志文章


    authors: Reed GH,Leyh TS

    更新日期:1980-11-25 00:00:00

  • Identification of residues in the monoclonal antitumor antibody L6 important for binding to its tumor antigen.

    abstract::L6 is a monoclonal antitumor antibody which recognizes an epitope located in a 42-residue extracellular domain of a tumor-associated approximately 22 kDa glycoprotein antigen. The L6 mAb localizes to solid tumors in vivo and triggers complement activation and antibody-dependent cellular cytotoxicity. It has been the s...


    pub_type: 杂志文章


    authors: Stenzel-Johnson PR,Yelton D,Bajorath J

    更新日期:1994-12-06 00:00:00

  • Peptide binding by calmodulin and its proteolytic fragments and by troponin C.

    abstract::Calmodulin and troponin C exhibit calcium-dependent binding of 1 mol/mol of dynorphin. The dissociation constants of the complexes, determined in 0.20 N KC1-1.0 mM CaCI2, pH 7.3, are 0.6 microM for calmodulin, 2.4 microM for rabbit fast skeletal muscle troponin C, and 9 microM for bovine heart troponin C. Experiments ...


    pub_type: 杂志文章


    authors: Malencik DA,Anderson SR

    更新日期:1984-05-22 00:00:00

  • Solution structure of the first intracellular loop of prostacyclin receptor and implication of its interaction with the C-terminal segment of G alpha s protein.

    abstract::The amino acids (residues 39-51) responsible for the interaction between the first intracellular loop (iLP1) of the human prostacyclin receptor (IP) and G alpha s protein have been identified [Zhang, L., Huang, G., Wu, J., and Ruan, K. H. (2005) Biochemistry 44, 11389-11401]. To further characterize the structural/fun...


    pub_type: 杂志文章


    authors: Zhang L,Wu J,Ruan KH

    更新日期:2006-02-14 00:00:00

  • Tubulin polymerization promoting proteins (TPPPs): members of a new family with distinct structures and functions.

    abstract::TPPP/p25 is a brain-specific protein, which induces tubulin polymerization and microtubule (MT) bundling and is enriched in Lewy bodies characteristic of Parkinson's disease [Tirián et al. (2003) Proc. Natl. Acad. Sci. U.S.A. 100, 13976-13981]. We identified two human gene sequences, CG1-38 and p25beta, which encoded ...


    pub_type: 杂志文章


    authors: Vincze O,Tökési N,Oláh J,Hlavanda E,Zotter A,Horváth I,Lehotzky A,Tirián L,Medzihradszky KF,Kovács J,Orosz F,Ovádi J

    更新日期:2006-11-21 00:00:00

  • Photooxidation pathway of chlorophyll Z in photosystem II as Studied by Fourier transform infrared spectroscopy.

    abstract::The oxidation pathway of chlorophyll Z (ChlZ) in photosystem II (PSII) at cryogenic temperatures was studied by means of light-induced Fourier transform infrared (FTIR) difference spectroscopy. To examine the involvement of redox-active beta-carotene (Car) in the pathway, two Car molecules in Mn-depleted PSII membrane...


    pub_type: 杂志文章


    authors: Kitajima Y,Noguchi T

    更新日期:2006-02-14 00:00:00