scholarly journals Redox-Mediated Post-Translational Modifications of Proteolytic Enzymes and Their Role in Protease Functioning

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 650
Author(s):  
Anastasiia I. Petushkova ◽  
Andrey A. Zamyatnin
Keyword(s):  
Redox Regulation ◽  
Proteolytic Enzymes ◽  
Post Translational Modifications ◽  
Regulated Cell Death ◽  
Age Related ◽  
Living Organisms ◽  
Dose Dependent ◽  
Hydrolysis Of ◽  
Flexible Dose ◽  
Dependent Mechanism

Proteolytic enzymes play a crucial role in metabolic processes, providing the cell with amino acids through the hydrolysis of multiple endogenous and exogenous proteins. In addition to this function, proteases are involved in numerous protein cascades to maintain cellular and extracellular homeostasis. The redox regulation of proteolysis provides a flexible dose-dependent mechanism for proteolytic activity control. The excessive reactive oxygen species (ROS) and reactive nitrogen species (RNS) in living organisms indicate pathological conditions, so redox-sensitive proteases can swiftly induce pro-survival responses or regulated cell death (RCD). At the same time, severe protein oxidation can lead to the dysregulation of proteolysis, which induces either protein aggregation or superfluous protein hydrolysis. Therefore, oxidative stress contributes to the onset of age-related dysfunction. In the present review, we consider the post-translational modifications (PTMs) of proteolytic enzymes and their impact on homeostasis.

EFFECT OF A FIBRIN-DERIVED PEPTIDE ON PULMONARY ANGIOTENSIN CONVERTING ENZYME (ACE) ACTIVITY AND ON PRESSURE RESPONSES TO BRADYKININ (BK)

1987 ◽  
Author(s):  
K Saldeen ◽  
R Moalli ◽  
T Saldeen
Keyword(s):  
Lung Injury ◽  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Proteolytic Enzymes ◽  
Common Finding ◽  
Pulmonary Arterial ◽  
Ace Activity ◽  
Isolated Lungs ◽  
Dose Dependent ◽  
Hydrolysis Of

Decreased ACE activity is a common finding in patients with adult respiratory distress syndrome (ARDS) and in animal models of lung injury. The nature of this effect is unknown. Fibrin, also a common finding in lung injury, is degraded to small peptides by proteolytic enzymes. Peptide 6A, corresponding to amino acid residues 43-47 of the BB-chain of fibrin (cgen), is produced by plasmin degradation of fibrin and has been shown to inhibit ACE in vitro. The purpose of the present investigation was to study whether peptide 6A inhibits pulmonary ACE in vivo and, if so, determine its effect of hemodynamic changes induced by bradykinin (BK) in the rabbit. We investigated the effect of peptide 6A an the hydrolysis of a synthetic ACE substrate, benzoyl-phe-ala-pro (BPAP) in anesthetized rabbits and in isolated lungs. Peptide 6A caused a reversible, dose-dependent inhibition of BPAP hydrolysis. The ID 50 for peptide 6A inhibition of ACE hydrolysis of BPAP was approximately 1 micrcmole.In both isolated rabbit lupgp and in the intact animal, BK injection elicited a dose dependent increase in pulmonary arterial pressure. In intact animals, this was accompanied by a dose dependent decrease in systemic arterial pressure.In both preparations, responses to BK were potentiated by addition of 1 micromole of peptide 6A. In isolated lungs, co-injection of peptide 6A significantly increased the pulmonary artery pressure response to every dose of BK except the highest (1 mg). In the anesthetized rabbit, 1 micromole of peptide 6A significantly (p<0.05) increased the pulmonary hypertensive response to 100 and 200 nanograms of BK and significantly (p<0.05) decreased the systemic hypotensive response following 100 , 200 , 300 and 400 nanograms of BK. The amount of BK needed to increase pulmonary arterial pressure was 1000-fold greater in the isolated lungs than in the intact animals. Peptides of this type might contribute to decreased ACE activity in patients with ARDS and may potentiate BK induced pulmonary hypertension and systemic hypotension in these patients.

Novel Approaches for Oral Delivery of Insulin and Current Status of Oral Insulin Products

2010 ◽  
Vol 3 (3) ◽  
pp. 1057-1064 ◽  
Author(s):  
Kinesh V P ◽  
Neelam D P ◽  
Punit B ◽  
Bhavesh S.B ◽  
Pragna K. S
Keyword(s):  
Diabetes Mellitus ◽  
Oral Delivery ◽  
Proteolytic Enzymes ◽  
Oral Route ◽  
The Body ◽  
Current Status ◽  
Intestinal Lumen ◽  
Insulin Administration ◽  
Novel Approaches ◽  
Dose Dependent

Diabetes mellitus is a serious pathologic condition that is responsible for major healthcare problems worldwide and costing billions of dollars annually. Insulin replacement therapy has been used in the clinical management of diabetes mellitus for more than 84 years. The present mode of insulin administration is by the subcutaneous route through which insulin is presented to the body in a non-physiological manner having many challenges. Hence novel approaches for insulin delivery are being explored. Challenges to oral route of insulin administration are: rapid enzymatic degradation in the stomach, inactivation and digestion by proteolytic enzymes in the intestinal lumen and poor permeability across intestinal epithelium because of its high molecular weight and lack of lipophilicity. Liposomes, microemulsions, nanocubicles, and so forth have been prepared for the oral delivery of insulin. Chitosan-coated microparticles protected insulin from the gastric environment of the body and released intestinal pH. Limitations to the delivery of insulin have not resulted in fruitful results to date and there is still a need to prepare newer delivery systems, which can produce dose-dependent and reproducible effects, in addition to increased bioavailability.

scholarly journals Implication of ferroptosis in aging

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Maryam Mazhar ◽  
Ahmad Ud Din ◽  
Hamid Ali ◽  
Guoqiang Yang ◽  
Wei Ren ◽  
...  
Keyword(s):  
Cell Death ◽  
Neurological Disorders ◽  
Accelerated Aging ◽  
Underlying Mechanism ◽  
Toxic Chemicals ◽  
Whole Body ◽  
Regulated Cell Death ◽  
Age Related ◽  
The Subject ◽  
Conventional Cell

AbstractLife is indeed continuously going through the irreversible and inevitable process of aging. The rate of aging process depends on various factors and varies individually. These factors include various environmental stimuli including exposure to toxic chemicals, psychological stress whereas suffering with various illnesses specially the chronic diseases serve as endogenous triggers. The basic underlying mechanism for all kinds of stresses is now known to be manifested as production of excessive ROS, exhaustion of ROS neutralizing antioxidant enzymes and proteins leading to imbalance in oxidation and antioxidant processes with subsequent oxidative stress induced inflammation affecting the cells, tissues, organs and the whole body. All these factors lead to conventional cell death either through necrosis, apoptosis, or autophagy. Currently, a newly identified mechanism of iron dependent regulated cell death called ferroptosis, is of special interest for its implication in pathogenesis of various diseases such as cardiovascular disease, neurological disorders, cancers, and various other age-related disorders (ARD). In ferroptosis, the cell death occur neither by conventional apoptosis, necrosis nor by autophagy, rather dysregulated iron in the cell mediates excessive lipid peroxidation of accumulated lethal lipids. It is not surprising to assume its role in aging as previous research have identified some solid cues on the subject. In this review, we will highlight the factual evidences to support the possible role and implication of ferroptosis in aging in order to declare the need to identify and explore the interventions to prevent excessive ferroptosis leading to accelerated aging and associated liabilities of aging.

scholarly journals Ferrous-glutathione coupling mediates ferroptosis and frailty in Caenorhabditis elegans

2019 ◽  
Author(s):  
Nicole L. Jenkins ◽  
Simon A. James ◽  
Agus Salim ◽  
Fransisca Sumardy ◽  
Terence P. Speed ◽  
...  
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Ferrous Iron ◽  
Somatic Tissue ◽  
Glutathione Depletion ◽  
Death Process ◽  
C Elegans ◽  
Regulated Cell Death ◽  
Age Related ◽  
Ageing Rate

All eukaryotes require iron. Replication, detoxification, and a cancer-protective form of regulated cell death termed ferroptosis1, all depend on iron metabolism. Ferrous iron accumulates over adult lifetime in the Caenorhabditis elegans model of ageing2. Here we show that glutathione depletion is coupled to ferrous iron elevation in these animals, and that both occur in late life to prime cells for ferroptosis. We demonstrate that blocking ferroptosis, either by inhibition of lipid peroxidation or by limiting iron retention, mitigates age-related cell death and markedly increases lifespan and healthspan in C. elegans. Temporal scaling of lifespan is not evident when ferroptosis is inhibited, consistent with this cell death process acting at specific life phases to induce organismal frailty, rather than contributing to a constant ageing rate. Because excess age-related iron elevation in somatic tissue, particularly in brain3–5, is thought to contribute to degenerative disease6, 7, our data indicate that post-developmental interventions to limit ferroptosis may promote healthy ageing.

scholarly journals Effect of Vernonia amygdalina on phospholipase activity from Naja Mossambica (Cobra)

2021 ◽  
Vol 6 (3) ◽  
pp. 053-060
Author(s):  
Abdullahi Abdulkakdir ◽  
Omeremime Elizabeth Dania ◽  
Bala Alkali Mohammed ◽  
Yahaya Abubakar Mohammed ◽  
Maimuna Bello Umar ◽  
...  
Keyword(s):  
Potent Inhibitor ◽  
Membrane Integrity ◽  
Maximal Velocity ◽  
Vernonia Amygdalina ◽  
Phospholipase Activity ◽  
Bioactive Agents ◽  
Dose Dependent ◽  
Hydrolysis Of ◽  
Menten Constant ◽  
Different Doses

Background: Phospholipases are one of the numerous enzymes found in the Naja mossambica venom. They play a major role in snakebite envenomation, and also responsible for the hydrolysis of a phospholipid, disrupting the membrane integrity. In this study, we evaluated the effect of Vernonia amygdalina on Phospholipase activity from Naja mossambica (Cobra) Results: Partially purified phospholipase had maximal velocity (Vmax) and Michaelis Menten constant (Km) of 7.6 × 10-5 mol/min and 1.7mg/ml, while the crude phospholipase had Vmax and Km of 9.4 × 10-5mol/min and 2.5mg/ml respectively. Inhibition study of aqueous extracts of Vernonia amygdalina leaf shows that the extract is a potent inhibitor of crude phospholipase in a dose-dependent pattern. The different doses of extract 15 %, 10 % and 5% produced percentage inhibition of 74.04 %, 78.6 % and 86.63% respectively. The kinetic binding constant (Ki) values of crude phospholipase for different concentrations of extracts 5%, 10% and 15% were 0.21mg/ml, 0.29mg/ml and 0.39mg/ml, while the partially purified phospholipase for different concentrations of extracts 5%, 10% and 15% were were 0.48mg/ml, 0.42mg/ml and 0.41mg/ml respectively. It can be deduced from the results that the extract inhibits the phospholipase activity in an uncompetitive manner. Conclusion: Aqueous extract of Vernonia amygdalina leaves may contain some bioactive agents that could serve as potent inhibitors of phospholipase from Naja mossambica venom.

scholarly journals Hydrolysis of14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

1983 ◽  
Vol 50 (2) ◽  
pp. 345-355 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Proteolytic Enzymes ◽  
Rumen Fluid ◽  
Performic Acid ◽  
Cross Linking ◽  
Acid Oxidation ◽  
Rumen Bacteria ◽  
Rate Of Hydrolysis ◽  
Micro Organisms ◽  
Hydrolysis Of

1. Proteins were labelled with14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with14C in this way are valid substrates for study with rumen micro-organisms.3. The patterns of digestion of14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.4. The rates of hydrolysis of a number of14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

Modulating a modulator: biogenic amines at subthreshold levels potentiate peptide-mediated cardioexcitation of the heart of the tobacco hawkmoth Manduca sexta.

1994 ◽  
Vol 197 (1) ◽  
pp. 377-391 ◽  
Author(s):  
K R Prier ◽  
O H Beckman ◽  
N J Tublitz
Keyword(s):  
Cyclic Amp ◽  
Manduca Sexta ◽  
Biogenic Amine ◽  
Molecular Mechanisms ◽  
Adult Heart ◽  
The Central Nervous System ◽  
Messenger System ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Dependent Mechanism

The central nervous system of the moth Manduca sexta contains a group of myoregulatory neuropeptides, the CAPs (Cardioacceleratory Peptides), which cause a physiologically important, dose-dependent increase in heart rate during wing inflation and flight in adult moths. We report here that the response of the adult heart to a subset of the CAPs, the CAP2S, is potentiated nearly twofold in the chronic presence of subthreshold levels of the biogenic amine octopamine or near-threshold levels of the biogenic amine serotonin. Subthreshold levels of the CAP2S fail to alter the response of the heart to octopamine. We have begun to investigate the molecular mechanisms underlying this potentiation. Previous work on the adult heart has shown that the CAP2s act through an inositol-1,4,5-trisphosphate second-messenger system. Here, we demonstrate that the cardioexcitatory effects of the two amines, in contrast to those of the CAP2S, are both mediated by cyclic AMP. Application to the heart of either 10(-5) moll-1 octopamine or 10(-6)moll-1 serotonin elicits a threefold increase in intracellular cyclic AMP levels. The CAP2S have no effect on cyclic AMP levels in the heart. These results illustrate a mechanism by which the effectiveness of a neurohormone can be increased with minimal cost to the animal. In Manduca sexta, subthreshold levels of octopamine are found in the haemolymph during wing inflation and flight. Thus, it is possible that octopamine up-regulates the effects of CAP2 via a cyclic-AMP-dependent mechanism during these activities.

Bradykinin stimulates ceramide production by activating specific BK-B1receptor in rat small artery

2002 ◽  
Vol 282 (1) ◽  
pp. H175-H183 ◽  
Author(s):  
Leonard Kleine ◽  
Gele Liu ◽  
Normand Leblanc ◽  
Richard L. Hébert
Keyword(s):  
Vascular Tone ◽  
Functional Change ◽  
Mesenteric Arteries ◽  
Dependent Manner ◽  
Small Artery ◽  
Mediated Effects ◽  
Ceramide Generation ◽  
Dose Dependent ◽  
Hydrolysis Of ◽  
Ceramide Production

Bradykinin (BK), a proinflammatory factor and vasodilator, causes functional change of the small artery. However, it is not clear whether any of these changes induced by BK are mediated by N-acetyl-d-sphingosine (ceramide). Therefore, we investigated whether BK affects the hydrolysis of sphingomyelin and generation of ceramide in the intact rat small artery. Our results suggest that BK induces sphingomyelin hydrolysis and increases ceramide production in a time- and dose-dependent manner. Relative to controls, BK causes a 50% decrease in sphingomyelin levels. Ceramide levels increase in response to BK with the highest level being obtained with 10−8M BK as well as similar amounts of ceramide are generated when exogenous sphingomyelinase (SMase) is added. We then determined which of the two BK receptors (BK-B1antagonist Lys-Des-Arg9-Leu8-BK or the BK-B2antagonist HOE-140) are implicated in the BK-induced generation of ceramide. The BK-B2antagonist did not alter the effect of BK on ceramide generation, whereas the BK-B1antagonist blocked the BK-induced production of ceramide. Although ceramide had no effect on KCl-induced constrictions, ceramide dilated preconstricted (phenylephrine) small pressurized rat mesenteric arteries by ∼40%. These results suggest that the activation of the BK-B1receptor mediates the BK-induced activation of SMase and of the production of ceramide. In conclusion, BK-mediated effects on vascular tone may be due, at least in part, to the increased production of ceramide.

scholarly journals Treating Senescence like Cancer: Novel Perspectives in Senotherapy of Chronic Diseases

2020 ◽  
Vol 21 (21) ◽  
pp. 7984
Author(s):  
Alessia Mongelli ◽  
Sandra Atlante ◽  
Veronica Barbi ◽  
Tiziana Bachetti ◽  
Fabio Martelli ◽  
...  
Keyword(s):  
Chronic Diseases ◽  
Cell Senescence ◽  
Biological Processes ◽  
Social Relevance ◽  
Chemical Agents ◽  
Age Related ◽  
Living Organisms ◽  
Specific Pathway

The WHO estimated around 41 million deaths worldwide each year for age-related non-communicable chronic diseases. Hence, developing strategies to control the accumulation of cell senescence in living organisms and the overall aging process is an urgently needed problem of social relevance. During aging, many biological processes are altered, which globally induce the dysfunction of the whole organism. Cell senescence is one of the causes of this modification. Nowadays, several drugs approved for anticancer therapy have been repurposed to treat senescence, and others are under scrutiny in vitro and in vivo to establish their senomorphic or senolytic properties. In some cases, this research led to a significant increase in cell survival or to a prolonged lifespan in animal models, at least. Senomorphics can act to interfere with a specific pathway in order to restore the appropriate cellular function, preserve viability, and to prolong the lifespan. On the other hand, senolytics induce apoptosis in senescent cells allowing the remaining non–senescent population to preserve or restore tissue function. A large number of research articles and reviews recently addressed this topic. Herein, we would like to focus attention on those chemical agents with senomorphic or senolytic properties that perspectively, according to literature, suggest a potential application as senotherapeutics for chronic diseases.

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