The oxidative reactivity of three manganese (III) porphyrin complexes with hydrogen peroxide and nitrite towards catalytic nitration of protein tyrosine

Metallomics ◽  
2021 ◽  
Author(s):  
Jiayu Li ◽  
Jingjing Wei ◽  
Zhonghong Gao ◽  
Guochuan Yin ◽  
Hailing Li
Keyword(s):  
Central Metal ◽  
Comprehensive Understanding ◽  
Protein Tyrosine ◽  
Catalytic Activities ◽  
Therapeutic Drugs ◽  
Oxidative Reactivity ◽  
Active Intermediate ◽  
Catalytic Nitration ◽  
Ph Dependent ◽  
Close Condition

Abstract Understanding the toxicological properties of MnIII-porphyrins (MnTPPS, MnTMPyP or MnTBAP) can provide important biochemical rationales in developing them as the therapeutic drugs against protein tyrosine nitration induced inflammation diseases. Here, we present a comprehensive understanding of the pH-dependent redox behaviors of these MnIII-porphyrins and their structural effects on catalyzing bovine serum albumin (BSA) nitration in the presence of H2O2 and NO2−. It was found that both MnTPPS and MnTBAP stand out in catalyzing BSA nitration at physiologically close condition (pH 8), yet they are less effective at pH 6 and 10. MnTMPyP was shown no ability to catalyze BSA nitration under all tested pHs (pH 6, 8 and 10). The kinetics and active intermediate determination through electrochemistry method revealed that both the pH-dependent redox behavior of the central metal cation and the antioxidant capability of porphin derivative contribute to the catalytic activities of three MnIII-porphyrins in BSA nitration in the presence of H2O2/NO2−. These comprehensive studies on the oxidative reactivity of MnIII-porphyrins towards BSA nitration may provide new clues for searching the manganese based therapeutic drugs against the inflammation related diseases.

scholarly journals pH-dependent effects of procaine on equine gamete activation†

2019 ◽  
Vol 101 (5) ◽  
pp. 1056-1074 ◽  
Author(s):  
Bart Leemans ◽  
Tom A E Stout ◽  
Ann Van Soom ◽  
Bart M Gadella
Keyword(s):  
Tyrosine Phosphorylation ◽  
Computer Assisted ◽  
Cell Organelle ◽  
Protein Tyrosine Phosphorylation ◽  
Weak Base ◽  
Cell Organelles ◽  
Protein Tyrosine ◽  
Sperm Analysis ◽  
Ph Dependent ◽  
Camp Levels

Abstract Procaine directly triggers pH-dependent cytokinesis in equine oocytes and induces hypermotility in stallion spermatozoa, an important event during capacitation. However, procaine-induced hyperactivated motility is abolished when sperm is washed to remove the procaine prior to sperm-oocyte co-incubation. To understand how procaine exerts its effects, the external Ca2+ and Na+ and weak base activity dependency of procaine-induced hyperactivation in stallion spermatozoa was assessed using computer-assisted sperm analysis. Percoll-washed stallion spermatozoa exposed to Ca2+-depleted (+2 mM EGTA) procaine-supplemented capacitating medium (CM) still demonstrated hyperactivated motility, whereas CM without NaCl or Na+ did not. Both procaine and NH4Cl, another weak base, were shown to trigger a cytoplasmic pH increase (BCECF-acetoxymethyl (AM)), which is primarily induced by a pH rise in acidic cell organelles (Lysosensor green dnd-189), accompanied by hypermotility in stallion sperm. As for procaine, 25 mM NH4Cl also induced oocyte cytokinesis. Interestingly, hyperactivated motility was reliably induced by 2.5–10 mM procaine, whereas a significant cytoplasmic cAMP increase and tail-associated protein tyrosine phosphorylation were only observed at 10 mM. Moreover, 25 mM NH4Cl did not support the latter capacitation characteristics. Additionally, cAMP levels were more than 10× higher in boar than stallion sperm incubated under similar capacitating conditions. Finally, stallion sperm preincubated with 10 mM procaine did not fertilize equine oocytes. In conclusion, 10 mM procaine causes a cytoplasmic and acidic sperm cell organelle pH rise that simultaneously induces hyperactivated motility, increased levels of cAMP and tail-associated protein tyrosine phosphorylation in stallion spermatozoa. However, procaine-induced hypermotility is independent of the cAMP/protein tyrosine phosphorylation pathway.

scholarly journals The Application of Reversible Intramolecular Sulfonamide Ligation to Modulate Reactivity in Organometallic Ruthenium(II) Diamine Complexes

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 244
Author(s):  
Samuel A. Kemp ◽  
Timothy J. Prior ◽  
Huguette Savoie ◽  
Ross W. Boyle ◽  
Benjamin S. Murray
Keyword(s):  
Healthy Tissue ◽  
Central Metal Atom ◽  
Dependent Manner ◽  
Central Metal ◽  
Coordination Environment ◽  
Typical Cell ◽  
Arene Ligand ◽  
Ph Conditions ◽  
Ph Dependent

Metallation of biomacromolecular species forms the basis for the anticancer activity of many metallodrugs. A major limitation of these compounds is that their reactivity is indiscriminate and can, in principle, occur in healthy tissue as well as cancerous tissue, potentially leading to side effects in vivo. Here we present pH-dependent intramolecular coordination of an arene-tethered sulfonamide functionality in organometallic ruthenium(II) ethylenediamine complexes as a route to controlling the coordination environment about the central metal atom. Through variation of the sulfonamide R group and the length of the tether linking it to the arene ligand the acidity of the sulfonamide NH group, and hence the pH-region over which regulation of metal coordination occurs, can be modulated. Intramolecular sulfonamide ligation controlled the reactivity of complex 4 within the physiologically relevant pH-region, rendering it more reactive towards 5ʹ-GMP in mildly acidic pH-conditions typical of tumour tissue compared to the mildly alkaline pH-conditions typical of healthy tissue. However, the activation of 4 by ring-opening of the chelate was found to be a slow process relative to the timescale of typical cell culture assays and members of this series of complexes were found not to be cytotoxic towards the HT-29 cell line. These complexes provide the basis for the development of analogues of increased potency where intramolecular sulfonamide ligation regulates reactivity and therefore cytotoxicity in a pH-dependent, and potentially, tissue-dependent manner.

Synthesis and catalytic properties of trans-A2B2-type metalloporphyrins in cyclohexane oxidation

2014 ◽  
Vol 92 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Yujia Xie ◽  
Fengyong Zhang ◽  
Pingle Liu ◽  
Fang Hao ◽  
He’an Luo
Keyword(s):  
Metal Ions ◽  
Catalytic Properties ◽  
Condensation Reaction ◽  
Catalytic Performance ◽  
Cyclohexane Oxidation ◽  
Central Metal ◽  
Reaction Conditions ◽  
Catalytic Activities ◽  
Cobalt Nickel

A new efficient and mild protocol for synthesizing a series of trans-A2B2-porphyrins through a TFA-catalyzed condensation reaction between various aldehydes and dipyrromethanes has been developed. Several trans-A2B2-metalloporphyrins (cobalt, nickel) were synthesized and used to catalyze cyclohexane oxidation C–H bonds with dioxygen in the absence of additives and solvents. The results show that the catalytic activities were relative to the nature of the substituted groups and the central metal ions of trans-A2B2-metalloporphyrin. Cobalt metalloporphyrin presents better catalytic performance in the conversion of cyclohexane than the nickel metalloporphyrin under the same reaction conditions.

Oxidative Reactivity Difference among the Metal Oxo and Metal Hydroxo Moieties: pH Dependent Hydrogen Abstraction by a Manganese(IV) Complex Having Two Hydroxide Ligands

2008 ◽  
Vol 130 (48) ◽  
pp. 16245-16253 ◽  
Author(s):  
Guochuan Yin ◽  
Andrew M. Danby ◽  
David Kitko ◽  
John D. Carter ◽  
William M. Scheper ◽  
...  
Keyword(s):  
Hydrogen Abstraction ◽  
Oxidative Reactivity ◽  
Ph Dependent

scholarly journals Control of Genetically Prescribed Protein Tyrosine Kinase Activities by Environment-Linked Redox Reactions

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Izumi Nakashima ◽  
Yoshiyuki Kawamoto ◽  
Kozue Takeda ◽  
Masashi Kato
Keyword(s):  
Tyrosine Kinases ◽  
Redox Reactions ◽  
Cell Activation ◽  
Tertiary Structure ◽  
Protein Tyrosine Phosphatases ◽  
Covalent Bond ◽  
Membrane Lipid ◽  
Protein Tyrosine ◽  
Signaling Systems ◽  
Catalytic Activities

Recent observations on environment-linked control of genetically prescribed signaling systems for either cell activation or cell death have been reviewed with a focus on the regulation of activities of protein tyrosine kinases (PTKs). The environment-linked redox reactions seem to primarily affect cell surface receptors and cell membrane lipid rafts, and they induce generation of reactive oxygen species (ROS) in cells. ROS thus generated might upregulate the catalytic activities of PTKs through inactivating protein tyrosine phosphatases that dephosphorylate and inactivate autophosphorylated PTKs. Recent evidence has, however, demonstrated that ROS could also directly oxidize SH groups of genetically conserved specific cysteines on PTKs, sometimes producing disulfide-bonded dimers of PTK proteins, either for upregulation or downregulation of their catalytic activities. The basic role of the redox reaction/covalent bond-mediated modification of protein tertiary structure-linked noncovalent bond-oriented signaling systems in living organisms is discussed.

Redox control of catalytic activities of membrane-associated protein tyrosine kinases

2005 ◽  
Vol 434 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Izumi Nakashima ◽  
Kozue Takeda ◽  
Yoshiyuki Kawamoto ◽  
Yusuke Okuno ◽  
Masashi Kato ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Protein Tyrosine Kinases ◽  
Redox Control ◽  
Protein Tyrosine ◽  
Catalytic Activities
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