pH-tuned metal coordination and peroxidase activity of a peptide dendrimer enzyme model with a Fe(ii)bipyridine at its core

2013 ◽  
Vol 11 (2) ◽  
pp. 344-352 ◽  
Author(s):  
Piero Geotti-Bianchini ◽  
Tamis Darbre ◽  
Jean-Louis Reymond
Keyword(s):  
Peroxidase Activity ◽  
Metal Coordination ◽  
Enzyme Model ◽  
Peptide Dendrimer

Remote control of bipyridine–metal coordination within a peptide dendrimer

2009 ◽  
pp. 6237 ◽  
Author(s):  
Nicolas A. Uhlich ◽  
Peter Sommer ◽  
Claudia Bühr ◽  
Stefan Schürch ◽  
Jean-Louis Reymond ◽  
...  
Keyword(s):  
Remote Control ◽  
Metal Coordination ◽  
Peptide Dendrimer

A Peptide Dendrimer Enzyme Model with a Single Catalytic Site at the Core

2007 ◽  
Vol 129 (43) ◽  
pp. 13238-13246 ◽  
Author(s):  
Sacha Javor ◽  
Estelle Delort ◽  
Tamis Darbre ◽  
Jean-Louis Reymond
Keyword(s):  
Catalytic Site ◽  
The Core ◽  
Enzyme Model ◽  
Peptide Dendrimer

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

Low Selenium Status in the Elderly Influences Thyroid Hormones

1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Thyroid Hormones ◽  
Peroxidase Activity ◽  
Controlled Trial ◽  
The Elderly ◽  
Serum Selenium ◽  
Selenium Status ◽  
Glutathione Peroxidase Activity ◽  
Double Blind ◽  
Double Blind Placebo

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.

Anion and solvent controlled growth of crystalline and amorphous zinc(II) coordination polymers and a molecular complex

2021 ◽  
Author(s):  
Claire Deville ◽  
Henrik Særkjær Jeppesen ◽  
Vickie McKee ◽  
Nina Lock
Keyword(s):  
Coordination Polymers ◽  
Molecular Complex ◽  
Research Field ◽  
Metal Coordination ◽  
Controlled Growth ◽  
Bottom Up ◽  
One Dimensional

Controlled bottom-up synthesis of amorphous coordination polymers with tailored metal coordination is a research field in its infancy. In this study, synthesis control was achieved to selectively prepare one-dimensional (1D)...

Sign in / Sign up

Export Citation Format

Share Document