Stability of metal ion complexes formed with methyl phosphate and hydrogen phosphate

Saha, Anil; Saha, Nabanita; Ji, Liang‐Nian; Zhao, Jing; Gregáň, Fridrich; Sajadi, S. A. A.; Song, Bin; Sigel, Helmut

doi:10.1007/s007750050048

Cited by 84 publications

(80 citation statements)

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“…S4), losing all or most of its water. In agreement with published reports (34,35), pP binds to Mn 2þ with an affinity constant roughly two-three orders of magnitude greater than Pi. Competition experiments show that Pi and pP bind competitively, with negligible formation of mixed-ligand complexes, justifying the formulation of Eq.…”

Section: Resultssupporting

confidence: 92%

Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

McNaughton

Reddi

Clement

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

115

143

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Manganese is an essential transition metal that, among other functions, can act independently of proteins to either defend against or promote oxidative stress and disease. The majority of cellular manganese exists as low molecular-weight Mn 2+ complexes, and the balance between opposing “essential” and “toxic” roles is thought to be governed by the nature of the ligands coordinating Mn 2+ . Until now, it has been impossible to determine manganese speciation within intact, viable cells, but we here report that this speciation can be probed through measurements of 1 H and 31 P electron-nuclear double resonance (ENDOR) signal intensities for intracellular Mn 2+ . Application of this approach to yeast ( Saccharomyces cerevisiae ) cells, and two pairs of yeast mutants genetically engineered to enhance or suppress the accumulation of manganese or phosphates, supports an in vivo role for the orthophosphate complex of Mn 2+ in resistance to oxidative stress, thereby corroborating in vitro studies that demonstrated superoxide dismutase activity for this species.

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Section: Resultssupporting

confidence: 92%

Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

McNaughton

Reddi

Clement

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

115

143

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“…The resulting straight lines are defined by equation (15). The equilibrium data for the methyl phosphate and the hydrogen phosphate systems fit on these same reference lines, including those for Cd(CH 3 OPO 3 ) and Cd(HOPO 3 ) [142], as do the data for RibMP 2-and for the pyrimidine-NMPs, UMP 2-and dTMP, given in Table 8 (see also Figure 11 below) [114,122].…”

Section: Properties Of Pyrimidine-nucleoside 5'-monophosphate Complexesmentioning

confidence: 98%

Complex Formation of Cadmium with Sugar Residues, Nucleobases, Phosphates, Nucleotides, and Nucleic Acids

Sigel

Skilandat

Sigel

et al. 2012

Cadmium: From Toxicity to Essentiality

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Cadmium(II), commonly classified as a relatively soft metal ion, prefers indeed aromaticnitrogen sites (e.g., N7 of purines) over oxygen sites (like sugar-hydroxyl groups). However, matters are not that simple, though it is true that the affinity of Cd(2+) towards ribose-hydroxyl groups is very small; yet, a correct orientation brought about by a suitable primary binding site and a reduced solvent polarity, as it is expected to occur in a folded nucleic acid, may facilitate metal ion-hydroxyl group binding very effectively. Cd(2+) prefers the guanine(N7) over the adenine(N7), mainly because of the steric hindrance of the (C6)NH(2) group in the adenine residue. This Cd(2+)-(N7) interaction in a guanine moiety leads to a significant acidification of the (N1)H meaning that the deprotonation reaction occurs now in the physiological pH range. N3 of the cytosine residue, together with the neighboring (C2)O, is also a remarkable Cd(2+) binding site, though replacement of (C2)O by (C2)S enhances the affinity towards Cd(2+) dramatically, giving in addition rise to the deprotonation of the (C4)NH(2) group. The phosphodiester bridge is only a weak binding site but the affinity increases further from the mono-to the di-and the triphosphate. The same also holds for the corresponding nucleotides. Complex stability of the pyrimidine-nucleotides is solely determined by the coordination tendency of the phosphate group(s), whereas in the case of purine-nucleotides macrochelate formation takes place by the interaction of the phosphate-coordinated Cd(2+) with N7. The extents of the formation degrees of these chelates are summarized and the effect of a non-bridging sulfur atom in a thiophosphate group (versus a normal phosphate group) is considered. Mixed ligand complexes containing a nucleotide and a further mono-or bidentate ligand are covered and it is concluded that in these species N7 is released from the coordination sphere of Cd(2+). In the case that the other ligand contains an aromatic residue (e.g., 2,2'-bipyridine or the indole ring of tryptophanate) intramolecular stack formation takes place. With buffers like Tris or Bistris mixed ligand complexes are formed. Cd(2+) coordination to dinucleotides and to dinucleoside monophosphates provides some insights regarding the interaction between Cd(2+) and nucleic acids. Cd(2+) binding to oligonucleotides follows the principles of coordination to its units. The available crystal studies reveal that N7 of purines is the prominent binding site followed by phosphate oxygens and other heteroatoms in nucleic acids. Due to its high thiophilicity, Cd(2+) is regularly used in so-called thiorescue experiments, which lead to the identification of a direct involvement of divalent metal ions in ribozyme catalysis.

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“…Acidification of a sample prior to IMAC anal-ysis protonates the carboxyl groups on the highly acidic amino acid residues and reduces nonspecific binding [47]. In most studies, 0.1-0.25 M acetic acid (pH ,2.7) has been used as a loading buffer for IMAC, however, Saha et al showed that the pKa value of phosphoric acid decreased to 1.1 upon methylation [55]. The pKa values of phosphopeptides would therefore be expected to be significantly lower than that of phosphoric acid due to the organic environment provided by the surrounding amino acid residues.…”

Section: Immobilized Metal Ion Affinity Chromatographymentioning

confidence: 99%

Analytical strategies for phosphoproteomics

2009

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Protein phosphorylation is a key regulator of cellular signaling pathways. It is involved in most cellular events in which the complex interplay between protein kinases and protein phosphatases strictly controls biological processes such as proliferation, differentiation, and apoptosis. Defective or altered signaling pathways often result in abnormalities leading to various diseases, emphasizing the importance of understanding protein phosphorylation. Phosphorylation is a transient modification, and phosphoproteins are often very low abundant. Consequently, phosphoproteome analysis requires highly sensitive and specific strategies. Today, most phosphoproteomic studies are conducted by mass spectrometric strategies in combination with phosphospecific enrichment methods. This review presents an overview of different analytical strategies for the characterization of phosphoproteins. Emphasis will be on the affinity methods utilized specifically for phosphoprotein and phosphopeptide enrichment prior to MS analysis, and on recent applications of these methods in cell biological applications.

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Stability of metal ion complexes formed with methyl phosphate and hydrogen phosphate

Cited by 84 publications

References 1 publication

Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Complex Formation of Cadmium with Sugar Residues, Nucleobases, Phosphates, Nucleotides, and Nucleic Acids

Analytical strategies for phosphoproteomics

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Stability of metal ion complexes formed with methyl phosphate and hydrogen phosphate

Cited by 84 publications

References 1 publication

Probing in vivo Mn2+speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Probing in vivo Mn2+speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Complex Formation of Cadmium with Sugar Residues, Nucleobases, Phosphates, Nucleotides, and Nucleic Acids

Analytical strategies for phosphoproteomics

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Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Probing in vivo Mn²⁺speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy