Hydrolysis of phosphate esters and anhydrides: role of metal ions

1987 ◽  
Vol 79 (3) ◽  
pp. 293-319 ◽  
Author(s):  
G.P. Haight
Keyword(s):  
Metal Ions ◽  
Phosphate Esters ◽  
Hydrolysis Of

scholarly journals Selective inhibition of Zn2+-glycerophosphocholine cholinephosphodiesterase by tellurium tetrachloride

1992 ◽  
Vol 284 (3) ◽  
pp. 641-643 ◽  
Author(s):  
D E Sok ◽  
M R Kim
Keyword(s):  
Metal Ions ◽  
Mouse Brain ◽  
Selective Inhibition ◽  
Inhibitory Effect ◽  
Physiological Conditions ◽  
Neutral Ph ◽  
Tellurium Tetrachloride ◽  
Hydrolysis Of ◽  
Competitive Pattern

A Zn(2+)-glycerophosphocholine cholinephosphodiesterase (EC 3.1.4.38) purified from mouse brain was found to be reversibly inhibited by tellurium tetrachloride. This effect was characterized by a competitive pattern of inhibition, with apparent Ki values of 0.7 microM and 1.5 microM for the hydrolysis of p-nitrophenylphosphocholine and glycerophosphocholine respectively. Interestingly, the inhibitory effect of tellurium tetrachloride was found to be greatly potentiated by tetramethylammonium salt, indicative of a synergistic interaction between the two compounds. Additionally, it was observed that the effect of tellurium tetrachloride was not affected by a number of other metal ions, and was more pronounced at neutral pH, suggesting that the inhibitory role of the tellurium tetrachloride may be of importance under physiological conditions. Thus Zn(2+)-glycerophosphocholine cholinephosphodiesterase is proposed to be one of the target enzymes which is susceptible to the inhibitory effect of tellurium tetrachloride.

Phosphorus metabolism in the coral–zooxanthellae symbiosis: characterization and possible roles of two acid phosphatases in the algal symbiont Symbiodinium sp

1989 ◽  
Vol 238 (1291) ◽  
pp. 193-202 ◽  
Keyword(s):  
Inorganic Phosphate ◽  
Physiological Role ◽  
Phosphate Esters ◽  
Phosphorus Metabolism ◽  
Acid Phosphatases ◽  
Hard Coral ◽  
Algal Symbiont ◽  
Acropora Formosa ◽  
Hydrolysis Of

Cell-free extracts of zooxanthellae ( Symbiodinium sp.) from the hard coral Acropora formosa contained two acid phosphatases that were resolved by affinity chromatography on concanavalin-A-Sepharose. The enzymes had similar properties, with the exception that phosphatase P-1 hydrolysed polyphosphate and pyrophosphate, whereas phosphatase P-2 had no activity towards either. The high activity of phosphatase P-1 with polyphosphate implies that the physiological role of this enzyme may be the mobilization of this phosphate storage compound. The physiological substrate of phosphatase P-2 is unknown, but the most likely role of this enzyme is the hydrolysis of phosphate esters exterior to the plasmalemma, before uptake of the released inorganic phosphate by the algal transport system. Cultured zooxanthellae ( S. kawagutii ) contained phosphatase P-2 only; the significance of this difference is unknown. The activities of P-1 and P-2 were always high in freshly isolated zooxanthellae, and both activities were repressed after incubation in phosphate-supplemented media. The implication is therefore that the algae in the coral-zooxanthellae symbiosis may be phosphate limited.

Adaptive Role of Lipids in Algae under Metal Ions Impact (a Review)

2018 ◽  
Vol 54 (6) ◽  
pp. 78-93
Author(s):  
V. V. Grubinko ◽  
O. I. Bodnar ◽  
A. I. Lutsiv ◽  
G. B. Viniarska
Keyword(s):  
Metal Ions ◽  
Adaptive Role

scholarly journals The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń
Keyword(s):  
Metal Ions ◽  
Coordination Mode ◽  
Transition Metal Ions ◽  
Disulfide Bridge ◽  
Chain Flexibility ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Cd Studies ◽  
Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

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