Conformational states of myo-inositol hexakis(phosphate) in aqueous solution. A carbon-13 NMR, phosphorus-31 NMR, and Raman spectroscopic investigation

Isbrandt, Lester R.; Oertel, Richard P.

doi:10.1021/ja00529a043

Cited by 84 publications

(61 citation statements)

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“…La valeur de S3'P : 0,20 ppm iI pH 3,5 diffkre de celle relevte dans la litttrature : 4,75 ppm iI pH 8. Toutefois la difftrence est conforme a ce qui a t t t gtntralement observt dans les phosphates de myo-inositol : un blindage quand la valeur du pH diminue (29). En revanche, les constantes de couplage 3~p-o-C-H 7,6 HZ et 7,3 Hz (litttrature) sont quasiment identiques.…”

Section: Per-phosphoranylationunclassified

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Duthu¹,

Houalla²,

Wolf³

1988

Can. J. Chem.

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Requ le 26 janvier 1988 BRIGITTE DUTHU, DOURAID HOUALLA et ROBERT WOLF. Can. J. Chem. 66, 2965Chem. 66, (1988. Nous dicrivons une rnCthode originale de phosphorylation du rnyo-inositol non protCgC, qui fournit plusieurs myo-inositol phosphates A la fois. Le schema reactionnel cornporte une phosphoranylation totale ou partielle du cyclitol, I'aide de l'arninobicyclophosphane 8, suivie d'une oxydation des bicyclophosphoranes liaison P-H obtenus et d'une hydrolyse acide des phosphates neutres qui en rCsultent. Dans le cas de la tris-phosphoranylation nous avons identifie, parmi les fractions sCparCes par HPLC, le myo-inositol-l,2(cycl) phosphate 22, le myo-inositol-1 phosphate 23 et le myo-inositol-2 phosphate 24.BRIGITTE DUTHU, DOURAID HOUALLA, and ROBERT WOLF. Can. J. Chem. 66, 2965Chem. 66, (1988. An original method for the phosphorylation of an unprotected myo-inositol is described, which yields several rnyo-inositol phosphates at the same time. The reaction proceeds via a partial or complete phosphoranylation of the cyclitol by means of the aminobicyclophosphane 8, followed by oxidation of the resulting bicyclophosphoranes bearing a P-H bond and acid hydrolysis of the neutral phosphates thus formed. In the case of the tris-phosphoranylation we identified, among the HPLC fractions, the myo-inositol-l,2-(cyc1)phosphate 22, the myo-inositol-1-phosphate 23, and the myo-inositol-2-phosphate 24.

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Section: Per-phosphoranylationunclassified

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Duthu¹,

Houalla²,

Wolf³

1988

Can. J. Chem.

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“…We used Eqn (2) to calculate KD at low and high pH by graphical integration of the curve shown in Fig. 2.…”

Section: Ph-stat Experimentsmentioning

confidence: 99%

“…However, due to the low affinity of P,-inositol for HbCO at this pH, AZ& could not be evaluated quantitatively. Application of Eqn (2) to the data in Fig. 4 shows that K&, has a minimum value at that pH where AZ& intersects the abscissa.…”

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Equilibrium Aspects of the Binding of myo‐Inositol Hexakisphosphate to Human Hemoglobin as Studied by ³¹P NMR and pH‐Stat Techniques

Zuiderweg¹,

Hamers

Bruin

et al. 1981

European Journal of Biochemistry

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The interaction of myo-inositol hexakisphosphate (P,-inositol) with human hemoglobin has been studied as a function of pH using pH-stat techniques and 31P NMR. With the pH-stat method the following data were obtained: the association constants for the P,-inositolldeoxyhemoglobin and P,-inositol/carboxyhemoglobin complexes at alkaline and acid pH respectively and the proton absorption curves associated with the protein/phosphate interaction for both complexes from pH 5.5 to pH 9. From these data the affinities of P,-inositol towards deoxyhemoglobin (Hb) and carboxyhemoglobin (HbCO) have been calculated as a function of pH. The shape of the proton absorption curves was found to be strongly dependent on the ligation state of the hemoglobin molecule.The pH dependence of the 31P N M R spectra of P,-inositol bound to Hb or HbCO provides a monitor for the proton-binding behaviour of the phosphate groups of P,-inositol when present in the central cavity of the protein. It appears that this behaviour is only slightly dependent on the ligation state of the hemoglobin molecule. The NMR spectral data were interpreted in terms of a model which takes into account the electrostatic interaction between the phosphate groups within the P,-inositol molecule as well as the electrostatic interaction between the phosphate groups and positively charged groups on the protein.To account for the discrepancy between the pH-stat and 31P N M R results, i.e. a strong dependence of the protonabsorption curves and a weak dependence of the proton-binding behaviour of P,-inositol on the ligation state of the protein respectively, it is proposed that a conformational change takes place in HbCO upon P,-inositol binding. Arnone and Perutz [S] showed that in deoxyhemoglobin P,-inositol binds to a cluster of eight positively charged residues located at the 8-chain side of the central cavity. Their analysis was confirmed by studies on the binding of P,-inositol to mutant hemoglobins. It was shown that the strength of binding depends on replacements of these residues [9-1 I]. At moderate ionic strength P,-inositol forms a tight 1 : 1 complex with deoxyhemoglobin. The association constant was found to be 1.6 x IO'M-l at pH7.3 in 0.1 M NaCl [12].Recent experiments showed that the binding site for polyphosphate molecules in ligated hemoglobin is also located at the entrance of the central cavity [I 3 -151. The stoichiometry of binding was found to be unity [13]. From oxygenation experiments [I 61 the affinity of P,-inositol towards ligated hemoglobin is known to be low at neutral pH.The proton-binding behaviour of P,-inositol free in solution was studied in detail in a previous paper [17]. It was shown that P,-inositol bears a 12-fold negative charge above pH 11 while all phosphate groups display an anomalous proton-binding behaviour below that pH. As was demonAbbreviations. P,-inositol, nzyo-inositol 1,2,3,4,5,6-hexisphosphate; Hb, deoxyhemoglobin; HbCO, carboxyhemoglobin; 3 1 P NMK, phosphorus nuclear magnetic resonance spectroscopy. strated, this anom...

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“…The dissociated form of the acid, which exists above a pH of 2, named phytate, is known to bind to a number of trace metals, colloidal clays and proteins [1][2][3][4][5]. These studies suggest that a phytate ion can bind to positively charged proteins and minerals since it occurs as a set of negatively charged species whose charge composition becomes more negative with increasing pH [1,6,7]. Seeds including cereals, legumes and nuts all contain phytate with concentrations ranging from 5 to 50 g per kg [8].…”

Section: Introductionmentioning

confidence: 99%

An isothermal titration calorimetry study of phytate binding to lysozyme

Darby

Platts

Daniel

et al. 2016

J Therm Anal Calorim

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Isothermal titration calorimetry (ITC) was used to detect phytate binding to the protein lysozyme. This binding interaction was driven by electrostatic interaction between the positively charged protein and negatively charged phytate. When two phytate molecules bind to the protein, the charge on the protein is neutralised and no further binding occurs. The stoichiometry of binding provided evidence of phytate-lysozyme complex formation that was temperature dependent, being most extensive at lower temperatures. The initial stage of phytate binding to lysozyme was less exothermic than later injections and had a stoichiometry of 0.5 at 313 K, which was interpreted as phytate crosslinking two lysozyme molecules with corresponding water displacement. ITC could make a valuable in vitro assay to understanding binding interactions and complex formation that normally occur in the stomach of monogastric animals and the relevance of drinking water temperature on the extent of phytate-protein interaction. Interpretation of ITC data in terms of cooperativity is also discussed.

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Conformational states of myo-inositol hexakis(phosphate) in aqueous solution. A carbon-13 NMR, phosphorus-31 NMR, and Raman spectroscopic investigation

Cited by 84 publications

References 4 publications

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Equilibrium Aspects of the Binding of myo‐Inositol Hexakisphosphate to Human Hemoglobin as Studied by ³¹P NMR and pH‐Stat Techniques

An isothermal titration calorimetry study of phytate binding to lysozyme

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Conformational states of myo-inositol hexakis(phosphate) in aqueous solution. A carbon-13 NMR, phosphorus-31 NMR, and Raman spectroscopic investigation

Cited by 84 publications

References 4 publications

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Phosphoranylation de polyols: Voie d'accès aux phosphates d'intérêt biologique. I. Cas du myo-inositol

Equilibrium Aspects of the Binding of myo‐Inositol Hexakisphosphate to Human Hemoglobin as Studied by 31P NMR and pH‐Stat Techniques

An isothermal titration calorimetry study of phytate binding to lysozyme

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Equilibrium Aspects of the Binding of myo‐Inositol Hexakisphosphate to Human Hemoglobin as Studied by ³¹P NMR and pH‐Stat Techniques