Putrescine Control of Peroxidase Activity in the Inductive Phase of Rooting in Poplar Shoots in vitro, and the Adversary Effect of Spermidine

The Gram-positive soil bacterium and cellulose degrader Streptomyces reticuli synthesizes the mycelium-associated enzyme CpeB, which displays haem-dependent catalase and peroxidase activity, as well as haem-independent manganese-peroxidase activity. The expression of the furS–cpeB operon depends on the redox regulator FurS and the presence of the haem-binding protein HbpS. Upstream of hbpS, the neighbouring senS and senR genes were identified. SenS is a sensor histidine kinase with five predicted N-terminally located transmembrane domains. SenR is the corresponding response regulator with a C-terminal DNA-binding motif. Comparative transcriptional and biochemical studies with a designed S. reticuli senS/senR chromosomal disruption mutant and a set of constructed Streptomyces lividans transformants showed that the presence of the novel two-component system SenS/SenR negatively modulates the expression of the furS–cpeB operon and the hbpS gene. The presence of SenS/SenR enhances considerably the resistance of S. reticuli to haemin and the redox-cycling compound plumbagin, suggesting that this system could participate directly or indirectly in the sensing of redox changes. Epitope-tagged HbpS (obtained from an Escherichia coli transformant) as well as the native S. reticuli HbpS interact in vitro specifically with the purified SenS fusion protein. On the basis of these findings, together with data deduced from the S. reticuli hbpS mutant strain, HbpS is suggested to act as an accessory protein that communicates with the sensor protein to modulate the corresponding regulatory cascade. Interestingly, close and distant homologues, respectively, of the SenS/SenR system are encoded within the Streptomyces coelicolor A3(2) and Streptomyces avermitilis genomes, but not within other known bacterial genomes. Hence the SenS/SenR system appears to be confined to streptomycetes.

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L-DOPA content, peroxidase activity, and response to H2O2 ofVicia faba L. andV. narbonensis L. in situ and in vitro

PROTOPLASMA ◽

10.1007/bf01539841 ◽

1990 ◽

Vol 154 (2-3) ◽

pp. 144-150 ◽

Cited By ~ 13

Author(s):

Cornelia Albrecht ◽

H. W. Kohlenbach

Keyword(s):

Peroxidase Activity ◽

Ofvicia Faba

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The Minimal Arsenic Concentration Required to Inhibit the Activity of Thyroid Peroxidase Activity In Vitro

Biological Trace Element Research ◽

10.1007/s12011-008-8183-y ◽

2008 ◽

Vol 126 (1-3) ◽

pp. 49-55 ◽

Cited By ~ 16

Author(s):

Dominic L. Palazzolo ◽

Kevin P. Jansen

Keyword(s):

Peroxidase Activity ◽

Arsenic Concentration ◽

Thyroid Peroxidase

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Some effects of vitamin E and selenium deprivation on tissue enzyme levels and indices of tissue peroxidation in rainbow trout (Salmo gairdneri)

British Journal Of Nutrition ◽

10.1079/bjn19850019 ◽

1985 ◽

Vol 53 (1) ◽

pp. 149-157 ◽

Cited By ~ 139

Author(s):

J. G. Bell ◽

C. B. Cowey ◽

J. W. Adron ◽

Aileen M. Shanks

Keyword(s):

Rainbow Trout ◽

Vitamin E ◽

Peroxidase Activity ◽

Cumene Hydroperoxide ◽

Dietary Vitamin ◽

Salmo Gairdneri ◽

Deficient Diet ◽

Exudative Diathesis ◽

Malondialdehyde Formation

1. Duplicate groups of rainbow trout (Salrno gairdnert) (mean weight 11 g) were given for 40 weeks one of four partially purified diets that were either adequate or low in selenium or vitamin E or both.2. Weight gains of trout given the dually deficient diet were significantly lower than those of trout given a complete diet or a diet deficient in Se. No mortalities occurred and the only pathology seen was exudative diathesis in the dually deficient trout.3. There was significant interaction between the two nutrients both with respect to packed cell volume and to malondialdehyde formation in the in vitro NADPH-dependent microsomal lipid peroxidation system.4. Tissue levels of vitamin E and Se decreased to very low levels in trout given diets lacking these nutrients. For plasma there was a significant effect of dietary vitamin E on Se concentration.5. Glutathione (GSH) peroxidase (EC 1. 1 1. 1.9) activity in liver and plasma was significantly lower in trout receiving low dietary Se but was independent of vitamin E intake. The ratios of hepatic GSH peroxidase activity measured with cumene hydroperoxide and hydrogen peroxide were the same for all treatments. This confirms the absence of a Se-independent GSH peroxidase activity in trout liver.6. Se deficiency did not lead to any compensatory increase in hepatic GSH transferase (EC 2. 5. 1. 18) activity; values were essentially the same in all treatments.7. Plasma pyruvate kinase (EC 2. 7. 1.40) activity increased significantly in the trout deficient in both nutrients. This was thought to be due to leakage of the enzyme from the muscle and may be indicative of incipient (subclinical) muscle damage.

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Jelly plug dissolution in Discoglossus pictus eggs (Anura) involves peroxidase-like activity and oxidative opening of disulphide bonds

Zygote ◽

10.1017/s0967199400001301 ◽

1993 ◽

Vol 1 (1) ◽

pp. 61-69 ◽

Cited By ~ 8

Author(s):

G. Pitari ◽

S. Dupré ◽

C. Fusco ◽

G. Maurizi ◽

C. Campanella

Keyword(s):

Hydrogen Peroxide ◽

Peroxidase Activity ◽

Electrophoretic Analysis ◽

Ringer Solution ◽

Cysteic Acid ◽

Jelly Coat ◽

Discoglossus Pictus ◽

Disulphide Bonds ◽

Sds Page

SummaryIn amphibian eggs the formation of a capsular chamber is one of the most striking events occurring either upon oviposition or after fertilisation. In the egg of the anuran Discoglossus pictus a capsular chamber forms following fertilisation or activation; the egg with its vitelline envelope rotates in this chamber according to gravity. Previous work showed that the chamber is the product of plug dissolution. The plug is a lens-shaped jelly coat, typical of Discoglossus, covering only part of the animal hemisphere. Its dissolution is caused by material released from the egg about 15 min after fertilisation through exocytosis of at least two types of vacuoles. Liquefaction of the plug correlates with the reduction of disulphide bonds present in the jelly matrix. In this study we investigated the nature of the substances released from the egg and some changes occurring in the plug during liquefaction. SDS-PAGE showed that the proteic profile of the plug changes dramatically after fertilisation, confirming proteic cleavage in the plug matrix during its dissolution. Through in vitro tests and electrophoretic analysis of the Ringer solution in which the egg exudate was collected, an increase in the activity of the solution was determined in the presence of hydrogen peroxide, and peroxidase activity was depicted in the egg exudate. The presence of free thiol groups and cysteic acid residues (or cysteine sulphinic acid) in the plugs of activated eggs was established, suggesting that during plug dissolution some disulphide bonds are oxidatively opened. This suggests that enzyme(s) with peroxidase activity are released following fertilisation. We surmise that such enzymes are contained in the intraovular vacuoles the exocytosis of which triggers the onset of plug liquefaction. The possible release of hydrogen peroxide from the egg is discussed.

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