Oxidation of myosin by haem proteins generates myosin radicals and protein cross-links

2008 ◽  
Vol 410 (3) ◽  
pp. 565-574 ◽  
Author(s):  
Marianne N. Lund ◽  
Catherine Luxford ◽  
Leif H. Skibsted ◽  
Michael J. Davies
Keyword(s):  
Oxidative Stress ◽  
Horseradish Peroxidase ◽  
Time Course ◽  
Product Formation ◽  
Food Samples ◽  
Meat Tenderness ◽  
Radical Species ◽  
Sds Page ◽  
Cross Links ◽  
Haem Proteins

Previous studies have reported that myosin can be modified by oxidative stress and particularly by activated haem proteins. These reactions have been implicated in changes in the properties of this protein in food samples (changes in meat tenderness and palatability), in human physiology (alteration of myocyte function and force generation) and in disease (e.g. cardiomyopathy, chronic heart failure). The oxidant species, mechanisms of reaction and consequences of these reactions are incompletely characterized. In the present study, the nature of the transient species generated on myosin as a result of the reaction with activated haem proteins (horseradish peroxidase/H2O2 and met-myoglobin/H2O2) has been investigated by EPR spectroscopy and amino-acid consumption, product formation has been characterized by HPLC, and changes in protein integrity have been determined by SDS/PAGE. Multiple radical species have been detected by EPR in both the presence and the absence of spin traps. Evidence has been obtained for the presence of thiyl, tyrosyl and other unidentified radical species on myosin as a result of damage-transfer from oxidized myoglobin or horseradish peroxidase. The generation of thiyl and tyrosyl radicals is consistent with the observed consumption of cysteine and tyrosine residues, the detection of di-tyrosine by HPLC and the detection of both reducible (disulfide bond) and non-reducible cross-links between myosin molecules by SDS/PAGE. The time course of radical formation on myosin, product generation and cross-link induction are consistent with these processes being interlinked. These changes are consistent with the altered function and properties of myosin in muscle tissue exposed to oxidative stress arising from disease or from food processing.

scholarly journals Time Course of Redox Biomarkers in COVID-19 Pneumonia: Relation with Inflammatory, Multiorgan Impairment Biomarkers and CT Findings

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1126
Author(s):  
Tijana Kosanovic ◽  
Dragan Sagic ◽  
Vladimir Djukic ◽  
Marija Pljesa-Ercegovac ◽  
Ana Savic-Radojevic ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Time Course ◽  
Redox Homeostasis ◽  
Original Data ◽  
Advanced Oxidation Protein Products ◽  
Oxidative Stress Parameters ◽  
Systemic Oxidative Stress ◽  
Dependent Relation ◽  
Organ Tissue ◽  
Insight Into

Although the original data on systemic oxidative stress in COVID-19 patients have recently started to emerge, we are still far from a complete profile of changes in patients’ redox homeostasis. We aimed to assess the extent of oxidative damage of proteins, lipids and DNA during the course of acute disease, as well as their association with CT pulmonary patterns. In order to obtain more insight into the origin of the systemic oxidative stress, the observed parameters were correlated with inflammatory biomarkers and biomarkers of multiorgan impairment. In this prospective study, we included 58 patients admitted between July and October 2020 with COVID-19 pneumonia. Significant changes in malondialdehyde, 8-hydroxy-2’-deoxyguanosine and advanced oxidation protein products levels exist during the course of COVID-19. Special emphasis should be placed on the fact that the pattern of changes differs between non-hospitalized and hospitalized individuals. Our results point to the time-dependent relation of oxidative stress parameters with inflammatory and multiorgan impairment biomarkers, as well as pulmonary patterns in COVID-19 pneumonia patients. Correlation between redox biomarkers and immunological or multiorgan impairment biomarkers, as well as pulmonary CT pattern, confirms the suggested involvement of neutrophils networks, IL-6 production, along with different organ/tissue involvement in systemic oxidative stress in COVID-19.

Time course of skeletal muscle loss and oxidative stress in rats with walker 256 solid tumor

2010 ◽  
Vol 42 (6) ◽  
pp. 950-958 ◽  
Author(s):  
Flávia A. Guarnier ◽  
Alessandra L. Cecchini ◽  
Andréia A. Suzukawa ◽  
Ana Leticia G.C. Maragno ◽  
Andréa N.C. Simão ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Solid Tumor ◽  
Time Course ◽  
Muscle Loss ◽  
Skeletal Muscle Loss ◽  
Walker 256 ◽  
And Oxidative Stress

scholarly journals The post-translational processing of chromogranin A in the pancreatic islet: involvement of the eukaryote subtilisin PC2

1994 ◽  
Vol 298 (3) ◽  
pp. 521-528 ◽  
Author(s):  
S D Arden ◽  
N G Rutherford ◽  
P C Guest ◽  
W J Curry ◽  
E M Bailyes ◽  
...  
Keyword(s):  
Secretory Granule ◽  
Pancreatic Islet ◽  
Pancreatic Beta Cells ◽  
Chromogranin A ◽  
Time Course ◽  
Deae Cellulose ◽  
Neuroendocrine Cells ◽  
Time Period ◽  
Sds Page

The post-translational processing of chromogranin A (CGA) and the nature of the enzyme(s) involved were investigated in rat pancreatic islet and insulinoma tissue. Pulse-chase radiolabelling experiments using sequence-specific antisera showed that the 98 kDa (determined by SDS/PAGE) precursor was processed to an N-terminal 21 kDa peptide, a C-terminal 14 kDa peptide and a 45 kDa centrally located peptide with a rapid time course (t1/2 approx. 30 min) after an initial delay of 30-60 min. The 45 kDa peptide was, in turn, converted partially into a 5 kDa peptide with pancreastatin immunoreactivity and a 3 kDa peptide with WE-14 immunoreactivity over a longer time period. Incubation of bovine CGA with rat insulinoma secretory-granule lysate produced peptides of 18, 16 and 40 kDa via intermediates of 65 and 55 kDa. N-terminal sequence analysis indicated that cleavage occurred at the conserved paired basic sites Lys114-Arg115 and Lys330-Arg331, suggesting that cleavage of the equivalent sites (Lys129-Arg130 and Lys357-Arg358) in the rat molecule produced the initial post-translational products observed in intact pancreatic beta-cells. The enzyme activity responsible for the cleavage of bovine CGA co-chromatographed on DEAE-cellulose with the type-2 proinsulin endopeptidase and with PC2 immunoreactivity. The type-1 enzyme (PC1/3) appeared inactive towards CGA. The requirement for Ca2+ ions and an acidic pH for conversion was consistent with the involvement of a member of the eukaryote subtilisin family, and the composition of the released peptides in pulse-chase and secretion studies suggested that conversion occurred in the secretory-granule compartment. The overall catalytic rate as well as the relative susceptibilities of the Lys114-Arg115 and Lys330-Arg331 sites to cleavage were affected by pH, suggesting that the ionic environment of the processing compartment may play a role in the differential processing of CGA which is evident in various neuroendocrine cells.

Mediators of mineralocorticoid receptor-induced profibrotic inflammatory responses in the heart

2009 ◽  
Vol 116 (9) ◽  
pp. 731-739 ◽  
Author(s):  
Peter Wilson ◽  
James Morgan ◽  
John W. Funder ◽  
Peter J. Fuller ◽  
Morag J. Young
Keyword(s):  
Oxidative Stress ◽  
Mrna Expression ◽  
Mineralocorticoid Receptor ◽  
Time Course ◽  
Cardiac Fibrosis ◽  
Inflammatory Responses ◽  
Receptor Activation ◽  
Mrna Levels ◽  
Tissue Remodelling ◽  
Perivascular Inflammation

Coronary, vascular and perivascular inflammation in rats following MR (mineralocorticoid receptor) activation plus salt are well-characterized precursors for the appearance of cardiac fibrosis. Endogenous corticosterone, in the presence of the 11βHSD2 (11β hydroxysteroid dehydrogenase type 2) inhibitor CBX (carbenoxolone) plus salt, produces similar inflammatory responses and tissue remodelling via activation of MR. MR-mediated oxidative stress has previously been suggested to account for these responses. In the present study we thus postulated that when 11βHSD2 is inhibited, endogenous corticosterone bound to unprotected MR in the vessel wall may similarly increase early biomarkers of oxidative stress. Uninephrectomized rats received either DOC (deoxycorticosterone), CBX or CBX plus the MR antagonist EPL (eplerenone) together with 0.9% saline to drink for 4, 8 or 16 days. Uninephrectomized rats maintained on 0.9% saline for 8 days served as controls. After 4 days, both DOC and CBX increased both macrophage infiltration and mRNA expression of the p22phox subunit of NADPH oxidase, whereas CBX, but not DOC, increased expression of the NOX2 (gp91phox) subunit. eNOS [endothelial NOS (NO synthase)] mRNA expression significantly decreased from 4 days for both treatments, and iNOS (inducible NOS) mRNA levels increased after 16 days of DOC or CBX; co-administration of EPL inhibited all responses to CBX. The responses characterized over this time course occurred before measurable increases in cardiac hypertrophy or fibrosis. The findings of the present study support the hypothesis that endogenous corticosterone in the presence of CBX can activate vascular MR to produce both inflammatory and oxidative tissue responses well before the onset of fibrosis, that the two MR ligands induce differential but overlapping patterns of gene expression, and that elevation of NOX2 subunit levels does not appear necessary for full expression of MR-mediated inflammatory and fibrogenic responses.

Time course of severe thyrotoxicosis in rats is marked by intense muscular oxidative stress and activation of chymotrypsin-like proteolysis

2012 ◽  
Vol 53 ◽  
pp. S154-S155
Author(s):  
S.S. Bernardes ◽  
F.A. Guarnier⁎ ◽  
P.C. Marinello ◽  
A.N.C. Simão ◽  
R. Cecchini ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Time Course

scholarly journals Differential activation of heat-shock and oxidation-specific stress genes in chemically induced oxidative stress

1995 ◽  
Vol 309 (2) ◽  
pp. 453-459 ◽  
Author(s):  
L Tacchini ◽  
G Pogliaghi ◽  
L Radice ◽  
E Anzon ◽  
A Bernelli-Zazzera
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Time Course ◽  
Consensus Sequence ◽  
Single Agent ◽  
Stress Protein ◽  
Hsp 70 ◽  
Activator Protein ◽  
Chemically Induced ◽  
Haem Oxygenase

Post-ischaemic reperfusion increases the level of the major heat-shock (stress) protein hsp 70 and of its mRNA by transcriptional mechanisms, and activates the binding of the heat-shock factor HSF to the consensus sequence HSE. In common with CoCl2 treatment, post-ischaemic reperfusion increases the level of haem oxygenase mRNA, an indicator of oxidative stress, but CoCl2 does not seem to induce the expression of the hsp 70 gene [Tacchini, Schiaffonati, Pappalardo, Gatti and Bernelli-Zazzera (1993) Lab. Invest. 68, 465-471]. Starting from these observations, we have now studied the expression of two genes of the hsp 70 family and of other possibly related genes under conditions of oxidative stress. Three different chemicals, which cause oxidative stress by various mechanisms and induce haem oxygenase, enhance the expression of the cognate hsc 73 gene, but do not activate the inducible hsp 70 gene. Expression of the other genes that have been studied seems to vary in intensity and/or time course, in relation to the particular mechanism of action of any single agent. The pattern of induction of the early-immediate response genes c-fos and c-jun observed during oxidative stress differs from that found in post-ischaemic reperfused livers. Oxidative-stress-inducing agents do not promote the binding of HSF to its consensus sequence HSE, such as occurs in heat-shock and post-ischaemic reperfusion, and fail to activate AP-1 (activator protein 1). With the possible exception of Phorone, the oxidative stress chemically induced in rat liver activates NFkB (nuclear factor kB) and AP-2 (activator protein 2) transcription factors.

scholarly journals cAMP induces a rapid and reversible modification of the chemotactic receptor in Dictyostelium discoideum.

1985 ◽  
Vol 100 (3) ◽  
pp. 715-720 ◽  
Author(s):  
C Klein ◽  
J Lubs-Haukeness ◽  
S Simons
Keyword(s):  
Dictyostelium Discoideum ◽  
Concentration Dependence ◽  
Time Course ◽  
Camp Synthesis ◽  
Sds Page ◽  
Reversible Modification ◽  
Camp Receptor ◽  
Camp Stimulation ◽  
Stimulation Of

Stimulation, within 1 min after cAMP stimulation, of aggregation-competent Dictyostelium discoideum amebae was found to cause a rapid (within 1 min) modification of the cell's surface cAMP receptor. The modified receptor migrated on SDS PAGE as a 47,000-mol-wt protein, as opposed to a 45,000-mol-wt protein labeled on unstimulated cells. The length of time this modified receptor could be detected depended upon the strength of the cAMP stimulus: 3-4 min after treatment with 10(-7) M cAMP, cells no longer possessed the 47,000-mol-wt form of the cAMP receptor. Instead, the 45,000-mol-wt form was present. Stimulation of cells with 10(-5) M cAMP, however, resulted in the persistent (over 15 min) expression of the modified receptor. The time course, concentration dependence, and specificity of stimulus for this cAMP-induced shift in the cAMP receptor were found to parallel the cAMP-stimulated phosphorylation of a 47,000-mol-wt protein. In addition, both phenomena were shown to occur in the absence of endogenous cAMP synthesis. The possibility that the cAMP receptor is phosphorylated in response to cAMP stimulation, and the role of this event in cell desensitization, are discussed.

Fragmentation of Actin by Thrombin-Like Snake Venom Proteases

1979 ◽  
Author(s):  
M. Hauck ◽  
L. Muszbek
Keyword(s):  
Skeletal Muscle ◽  
Amino Acid ◽  
Snake Venom ◽  
Time Course ◽  
Peptide Bond ◽  
Muscle Actin ◽  
Sds Page ◽  
End Groups ◽  
Bothrops Marajoensis ◽  
Bothrops Moojeni

It has been demonstrated that thrombin can split skeletal muscle actin (Muszbek and Laki, PNAS 1974,71,2208). In the present paper the effect of thrombin-like snake venom proteases (Ancrod and Batroxobins of Bothrops moojeni and Bothrops marajoensis) on actin was studied and compared to the thrombic cleavage of this protein. Only EDTA pretreated G and F actin were split by Ancrod, while, Batroxobins hydrolized native G actin, too. The time course of digestion was followed by SDS PAGE. A split product of 37500 m.w. appeared first which was cleaved further resulting in three lower m.w. fragments. The SDS gel pattern of thrombic fragmentation was well distinguishable from those caused by Ancrod and Batroxobins. The first split products of Batroxobin digestion were isolated and by estimating their N-, and C-terminal end groups and amino acid compositions the peptide bond hydrolyzed first was located in the primary structure of actin. It was established that while thrombin split off two actinopeptides (at Arg ( 28)-Ala(29) and Arg ( 39)-His ( 40) from the N-terminal end of the molecule only Arg ( 39)-His ( 40) was cleaved by Batroxobins.

scholarly journals Elasticity and energy dissipation in the double network hydrogel adhesive of the slug Arion subfuscus

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190201 ◽  
Author(s):  
T.-M. Fung ◽  
C. Gallego Lazo ◽  
A. M. Smith
Keyword(s):  
Energy Dissipation ◽  
Time Course ◽  
Tensile Tests ◽  
Cyclic Stress ◽  
Mechanical Tests ◽  
Double Network ◽  
Ph Values ◽  
Arion Subfuscus ◽  
Synthetic Adhesives ◽  
Cross Links

The slug Arion subfuscus produces a mucus-based defensive secretion that is remarkably tough. This glue appears to be a double network hydrogel, gaining its toughness through the synergistic actions of two networks of polymers, a relatively stiff network and a relatively deformable network. The double network mechanism has great potential to guide the development of synthetic adhesives. Mechanical tests were performed to analyse key predictions of the mechanism. Stress relaxation tests and tensile tests support the presence of stable cross-links. Cyclic stress–strain tests demonstrate that the glue dissipates a great deal of energy through the failure of these cross-links as sacrificial bonds. Energy dissipation by failure of sacrificial bonds rather than viscous processes is supported by the minimal effect of the time course of the experiments on the measured properties. These sacrificial bonds appear able to reform within minutes after failure. Finally, the glue's stiffness decreases at pH values below 5.5, whereas magnesium and calcium rapidly dissociate from the glue at all pH values tested. Thus, these ions may not be the primary cross-linkers generating the glue's stiffness. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

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