The pH behavior of a 2-aminoethyl dihydrogen phosphate zwitterion studied with NMR-titrations

Myller, A.T.; Karhe, J.J.; Haukka, Matti; Pakkanen, Tuula T.

doi:10.1016/j.molstruc.2012.08.033

Cited by 18 publications

(15 citation statements)

References 37 publications

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“…The structures of the studied ligands are presented in Table 1 and the values of successive protonation constants of phosphoethanolamine (enP) are presented in Table 2 . Corresponding respectively to the protonation of -NH 2 and -O-PO 3 2− , logK 1 had a value of 10.41 and logK 2 had a value of 5.70, which were determined by computer calculations from titration data and are consistent with the literature data [ 32 , 33 , 34 ].…”

Section: Resultssupporting

confidence: 80%

The Influence of pH on Complexation Process of Copper(II) Phosphoethanolamine to Pyrimidine Nucleosides

et al. 2021

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The influence of pH on the complex formation of phosphoethanolamine and pyrimidine nucleosides (uridine, cytidine and thymidine) with copper(II) ions was studied. All investigations were performed in aqueous solution. The overall stability constants of the complexes and non-covalent compounds were obtained using the potentiometric method with computer calculation of the data. Moreover, equilibrium constants of the reaction were determined. The mode of coordination was obtained using spectroscopic methods. Analysis of the potentiometric and spectroscopic data confirmed the involvement and effectiveness of phosphate groups in species formation as well as the influence of pH on the mode of coordination of the investigated biomaterials. In the next step, studied complexes will be applied as potential biomaterials with biological applications.

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Section: Resultssupporting

confidence: 80%

The Influence of pH on Complexation Process of Copper(II) Phosphoethanolamine to Pyrimidine Nucleosides

et al. 2021

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“…One reasonable possibility is that K M may depend on the protonation of the PEA phosphate moiety (which is dianionic at neutral pH but would become monoanionic at acidic pH). Since the calculated apparent pK a is higher than the pK a2 of the phosphoryl group of free PEA (~6 [22]), contributions from ionizable groups on the enzyme are also possible. Alternatively or additionally, the discrepancy may in principle have a kinetic origin, as K M is a combination of kinetic constants which may be differently affected by pH.…”

Section: Resultsmentioning

confidence: 96%

Kinetic characterization of the human O‐phosphoethanolamine phospho‐lyase reveals unconventional features of this specialized pyridoxal phosphate‐dependent lyase

2014

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Human O-phosphoethanolamine (PEA) phospho-lyase is a pyridoxal 5 0 -phosphate (PLP) dependent enzyme that catalyzes the degradation of PEA to acetaldehyde, phosphate and ammonia. Physiologically, the enzyme is involved in phospholipid metabolism and is expressed mainly in the brain, where its expression becomes dysregulated in the course of neuropsychiatric diseases. Mechanistically, PEA phospho-lyase shows a remarkable substrate selectivity, strongly discriminating against other amino compounds structurally similar to PEA. Herein, we studied the enzyme under steady-state and pre-steady-state conditions, analyzing its kinetic features and getting insights into the factors that contribute to its specificity. The pH dependence of the catalytic parameters and the pattern of inhibition by the product phosphate and by other anionic compounds suggest that the active site of PEA phospho-lyase is optimized to bind dianionic groups and that this is a prime determinant of the enzyme specificity towards PEA. Single-and multiple-wavelength stopped-flow studies show that upon reaction with PEA the main absorption band of PLP (k max = 412 nm) rapidly blue-shifts to~400 nm. Further experiments suggest that the newly formed and rather stable 400-nm species most probably represents a Michaelis (noncovalent) complex of PEA with the enzyme. Accumulation of such an early intermediate during turnover is unusual for PLP-dependent enzymes and appears counterproductive for absolute catalytic performance, but it can contribute to optimize substrate specificity. PEA phospho-lyase may hence represent a case of selectivity-efficiency tradeoff. In turn, the strict specificity of the enzyme seems important to prevent inactivation by other amines, structurally resembling PEA, that occur in the brain.

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“…According to the reported pK a for this compound, at pH ≈ 7 the phosphate group will be deprotonated and the amine group will be positively charged [54]. This will allow an electrostatic interaction and/or hydrogen bonding between the surface and the monoprotonate phosphate group.…”

Section: Discussionmentioning

confidence: 99%

Simple route for nano-hydroxyapatite properties expansion

et al. 2015

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Simple surface modification of nano-hydroxyapatite, through acid-basic reactions, allows expanding the properties of this material. Introduction of organic groups such as hydrophobic alkyl chains, carboxylic acid, and amide or amine basic groups on the hydroxyapatite surface systematically change the polarity, surface area, and reactivity of hydroxyapatite without modifying its phase. Physical and chemical properties of the new derivative particles were analyzed. The biocompatibility of modified Nano-Hap on Raw 264.7 cells was also assessed.

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The pH behavior of a 2-aminoethyl dihydrogen phosphate zwitterion studied with NMR-titrations

Cited by 18 publications

References 37 publications

The Influence of pH on Complexation Process of Copper(II) Phosphoethanolamine to Pyrimidine Nucleosides

The Influence of pH on Complexation Process of Copper(II) Phosphoethanolamine to Pyrimidine Nucleosides

Kinetic characterization of the human O‐phosphoethanolamine phospho‐lyase reveals unconventional features of this specialized pyridoxal phosphate‐dependent lyase

Simple route for nano-hydroxyapatite properties expansion

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