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Molecules (Basel, Switzerland) Aug 2023The lysozyme in the chicken egg white consists of various bioactive amino acids. However, these compounds are inactive when they are in the sequence of parent proteins....
The lysozyme in the chicken egg white consists of various bioactive amino acids. However, these compounds are inactive when they are in the sequence of parent proteins. They become active only when isolated from these proteins. The aim of this study was to modify lysozyme with proteolytic enzymes under specific conditions of the reaction environment so as to obtain active biopeptides. The physicochemical properties of the resulting preparations were also assessed. Our study showed that the modification of lysozyme with hydrolytic enzymes (pepsin and trypsin) under strictly specified conditions resulted in obtaining biopeptide preparations with new and valuable properties, as compared with native lysozyme. After the enzymatic modification of lysozyme, two structural fractions were distinguished in the composition of the resulting preparations-the monomeric fraction and the peptide fraction. The modified lysozyme exhibited high surface hydrophobicity and high total antibacterial activity despite the decrease in the hydrolytic activity. Modification of lysozyme with hydrolytic enzymes, especially pepsin, resulted in preparations with very good antioxidative properties.
Topics: Muramidase; Peptide Hydrolases; Pepsin A; Hydrolysis; Dermatologic Agents
PubMed: 37687089
DOI: 10.3390/molecules28176260 -
Clinical Journal of Gastroenterology Dec 2014Laryngopharyngeal reflux (LPR) is an extraesophageal manifestation of gastroesophageal reflux disease (GERD). With the increase of GERD patients, the importance of LPR... (Review)
Review
Laryngopharyngeal reflux (LPR) is an extraesophageal manifestation of gastroesophageal reflux disease (GERD). With the increase of GERD patients, the importance of LPR is acknowledged widely. However, the pathophysiology of LPR is not understood completely and the diagnostic criteria for LPR remain controversial. Unfortunately, a gold standard diagnostic test for reflux laryngitis is not available. Recently, an experimental animal model for reflux laryngitis was developed to investigate the pathophysiology of reflux laryngitis. An empirical trial of lifestyle modification and proton pump inhibitor therapy is a reasonable approach for LPR symptoms. Alternatives after failure with aggressive medical treatment are limited and multichannel intraluminal impedance and pH monitoring is currently the best alternative to detect nonacid reflux. Additional prospective and evidence-based research is anticipated.
Topics: Animals; Disease Models, Animal; Esophageal pH Monitoring; Fundoplication; Health Behavior; Humans; Laryngopharyngeal Reflux; Laryngoscopy; Life Style; Male; Pepsin A; Proton Pump Inhibitors
PubMed: 25491904
DOI: 10.1007/s12328-014-0535-x -
Brazilian Journal of Otorhinolaryngology 2023Salivary pepsin has emerged as a biomarker for Laryngopharyngeal Reflux (LPR), which, however, has been questioned for its efficacy due to a lack of supporting medical... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Salivary pepsin has emerged as a biomarker for Laryngopharyngeal Reflux (LPR), which, however, has been questioned for its efficacy due to a lack of supporting medical data. Therefore, this study analyzed the diagnostic value of salivary pepsin for LPR and assessed a better cutoff value.
METHODS
Studies were searched in PubMed, Embase, and Cochrane Library from their receptions to October 1, 2021. Then, RevMan 5.3 and Stata 14.0 were utilized to summarize the diagnostic indexes for further meta-analysis. Data were separately extracted by two reviewers according to the trial data extraction form of the Cochrane Handbook. The risk of bias in Randomized Control Trials (RCTs) was evaluated with the Cochrane Risk of Bias Tool.
RESULTS
A total of 16 studies matched the criteria and were subjected to meta-analysis. The results revealed a pooled sensitivity of 61% (95% CI 50%-71%), a pooled specificity of 67% (95% CI 48%-81%), a positive likelihood ratio of 2 (95% CI 1.2-2.8), a negative likelihood ratio of 0.58 (95% CI 0.47‒0.72), and the area under the receiver operating characteristic curve of 0.67 (95% CI 0.63‒0.71). Subgroup analyses indicated that the cutoff value of pepsin at 50 ng/mL had a higher degree of diagnostic accuracy than that of pepsin at 16 ng/mL in cohort studies.
CONCLUSION
The review demonstrated low diagnostic performance of salivary pepsin for LPR and that the cutoff value of 50 ng/mL pepsin had superior diagnostic accuracy. Nevertheless, the diagnostic value may vary dependent on the utilized diagnostic criteria. Therefore, additional research is needed on the improved way of identifying salivary pepsin in the diagnosis of LPR, and also longer-term and more rigorous RCTs are warranted to further assess the effectiveness of salivary pepsin.
Topics: Humans; Laryngopharyngeal Reflux; Pepsin A; Saliva; ROC Curve; Biomarkers
PubMed: 36347787
DOI: 10.1016/j.bjorl.2022.10.050 -
International Journal of Biological... Feb 2023Proteolysis of amyloids is related to prevention and treatment of amyloidosis. What if the conditions for proteolysis were the same to those for amyloid formation? For...
Proteolysis of amyloids is related to prevention and treatment of amyloidosis. What if the conditions for proteolysis were the same to those for amyloid formation? For example, pepsin, a gastric protease is activated in an acidic environment, which, interestingly, is also a condition that induces the amyloid formation. Here, we investigate the competition reactions between proteolysis and synthesis of amyloid under pepsin-activated conditions. The changes in the quantities and nanomechanical properties of amyloids after pepsin treatment were examined by fluorescence assay, circular dichroism and atomic force microscopy. We found that, in the case of pepsin-resistant amyloid, a secondary reaction can be accelerated, thereby proliferating amyloids. Moreover, after this reaction, the amyloid became 32.4 % thicker and 24.2 % stiffer than the original one. Our results suggest a new insight into the proteolysis-driven proliferation and rigidification of pepsin-resistant amyloids.
Topics: Proteolysis; Pepsin A; Amyloid; Peptide Hydrolases; Circular Dichroism; Amyloidogenic Proteins; Cell Proliferation; Microscopy, Atomic Force
PubMed: 36543295
DOI: 10.1016/j.ijbiomac.2022.12.104 -
Scandinavian Journal of Rheumatology Jan 2023Rheumatoid arthritis (RA) is characterized by systemic inflammation and the presence of anti-citrullinated protein antibodies (ACPAs), which contain remarkably high...
OBJECTIVE
Rheumatoid arthritis (RA) is characterized by systemic inflammation and the presence of anti-citrullinated protein antibodies (ACPAs), which contain remarkably high levels of Fab glycosylation. Anti-hinge antibodies (AHAs) recognize immunoglobulin G (IgG) hinge neoepitopes exposed following cleavage by inflammation-associated proteases, and are also frequently observed in RA, and at higher levels compared to healthy controls (HCs). Here, we investigated AHA specificity and levels of Fab glycosylation as potential immunological markers for RA.
METHOD
AHA serum levels, specificity, and Fab glycosylation were determined for the IgG-hinge cleaved by matrix metalloproteinase-3, cathepsin G, pepsin, or IdeS, using enzyme-linked immunosorbent assay and lectin affinity chromatography, in patients with early active RA (n = 69) and HCs (n = 97).
RESULTS
AHA reactivity was detected for all hinge neoepitopes in both RA patients and HCs. Reactivity against CatG-IgG-F(ab´)s and pepsin-IgG-F(ab´)s was more prevalent in RA. Moreover, all AHA responses showed increased Fab glycosylation levels in both RA patients and HCs.
CONCLUSIONS
AHA responses are characterized by elevated levels of Fab glycosylation and highly specific neoepitope recognition, not just in RA patients but also in HCs. These results suggest that extensive Fab glycosylation may develop in response to an inflammatory proteolytic microenvironment, but is not restricted to RA.
Topics: Humans; Glycosylation; Pepsin A; Anti-Citrullinated Protein Antibodies; Immunoglobulin G; Arthritis, Rheumatoid; Inflammation; Autoantibodies
PubMed: 34726124
DOI: 10.1080/03009742.2021.1986959 -
European Archives of... Mar 2022We investigated the role of Glut-1 and H/K-ATPase expression in pepsin-induced development of human vocal cord leukoplakia cells (HVCLCs). Next, we analyzed the...
PURPOSE
We investigated the role of Glut-1 and H/K-ATPase expression in pepsin-induced development of human vocal cord leukoplakia cells (HVCLCs). Next, we analyzed the relationship between Glut-1 and H/K-ATPase expression with the clinicopathological features of laryngeal carcinoma.
METHODS
Glut-1 and H/K-ATPase expression levels in HVCLCs were determined after treatment with artificial gastric juice containing pepsin and laryngeal carcinoma tissues.
RESULTS
Exposure to pepsin-containing artificial gastric juice significantly enhanced the migration and proliferation of VSCLCs in a time-dependent manner. The apoptotic rate of VSCLCs decreased over time after exposure to pepsin and reached a nadir on day 7 (p < 0.01). With increasing duration of exposure to pepsin, the proportion of VSCLCs in G0/G1 phase decreased and the proportions in the S and G2/M phases significantly increased (p < 0.05). After treatment with pepsin-containing artificial gastric juice, RT-PCR and Western blotting showed that the expression of Glut-1 and H/K-ATPase α, β significantly increased in HVCLCs compared to in the absence of pepsin (p < 0.05). The expression of Glut-1 and H/K-ATPase α, β gradually increased from vocal cord leukoplakia (VLC) to laryngeal carcinoma (p < 0.05). Lentivirus-mediated inhibition of Glut-1 expression in VCL significantly inhibited the cells' migration and proliferation (p < 0.05) but enhanced their apoptosis (p < 0.05). Also, inhibition of Glut-1 expression resulted in an increased proportion of cells in G0/G1 phase and a significantly decreased proportion in G2/M phase (p < 0.05).
CONCLUSIONS
Elevated Glut-1 expression may promote the development of VCL by upregulating laryngeal H/K-ATPase expression to reactivate absorbed pepsin, thus damaging the laryngeal mucosa.
Topics: Adenosine Triphosphatases; Glucose Transporter Type 1; H(+)-K(+)-Exchanging ATPase; Humans; Laryngeal Neoplasms; Laryngopharyngeal Reflux; Leukoplakia; Pepsin A; Vocal Cords
PubMed: 34800155
DOI: 10.1007/s00405-021-07172-y -
International Journal of Biological... Jun 2022Pepsin is a protease used in many different applications, and in many instances, it is utilized in an immobilized form to prevent contamination of the reaction product.... (Review)
Review
Pepsin is a protease used in many different applications, and in many instances, it is utilized in an immobilized form to prevent contamination of the reaction product. This enzyme has two peculiarities that make its immobilization complex. The first one is related to the poor presence of primary amino groups on its surface (just one Lys and the terminal amino group). The second one is its poor stability at alkaline pH values. Both features make the immobilization of this enzyme to be considered a complicated goal, as most of the immobilization protocols utilize primary amino groups for immobilization. This review presents some of the attempts to get immobilized pepsin biocatalyst and their applications. The high density of anionic groups (Asp and Glu) make the anion exchange of the enzyme simpler, but this makes many of the strategies utilized to immobilize the enzyme (e.g., amino-glutaraldehyde supports) more related to a mixed ion exchange/hydrophobic adsorption than to real covalent immobilization. Finally, we propose some possibilities that can permit not only the covalent immobilization of this enzyme, but also their stabilization via multipoint covalent attachment.
Topics: Enzyme Stability; Enzymes, Immobilized; Glutaral; Hydrogen-Ion Concentration; Pepsin A
PubMed: 35508226
DOI: 10.1016/j.ijbiomac.2022.04.224 -
Journal of Voice : Official Journal of... Jul 2023Laryngopharyngeal reflux-associated symptoms embrace a wide variety of head and neck manifestations. Its participation in eye disorders has recently been postulated, and... (Review)
Review
BACKGROUND
Laryngopharyngeal reflux-associated symptoms embrace a wide variety of head and neck manifestations. Its participation in eye disorders has recently been postulated, and there is currently no consensus in this regard. The aim of this manuscript is to review the role of reflux in the development of ocular signs and symptoms, and its physio-pathological mechanisms.
METHODS
A systematic approach based on the preferred reporting Items for a systematic review and meta-analysis checklist with a modified population, intervention, comparison, and outcome framework was used to structure the review process of studies that evaluated the possible association, with clear diagnostic methods, of laryngopharyngeal reflux and ocular signs and symptoms. Search was conducted in different indexed databases (PubMed/MEDLINE, the Cochrane Library, Scielo and Web of Science) and through the meta-searcher Trip Database with the keywords: reflux, laryngitis, laryngopharyngeal, gastroesophageal, ocular, eye, symptoms, signs, conjunctivitis, keratitis, dacryocystitis, dry eye.
RESULTS
Seven studies met the inclusion criteria, in which the primary acquired nasolacrimal duct obstruction and the ocular surface disease were evaluated. The local increase of eye pepsin concentration (>2.5 ng/mL) may affect ocular surface though its direct proteolytic activity and the local expression of proinflammatory cytokines. The H. Pylori, with a similar mechanism to reach the lacrimonasal duct, would be associated with the release of proinflammatory and vasoactive substances that would lead to a mucosa injury and chronic inflammation. Ocular Surface Disease Index seems to correlate directly with the reflux severity, with cut-off of 41.67 score as predictor for disease.
DISCUSSION
The role of laryngopharyngeal reflux in the development of ocular disorders has not yet been demonstrated and data are limited and heterogeneous. It seems theoretically conceivable that pepsin may reach lachrymal duct area through hypopharyngeal-nasal gaseous reflux events. Future studies using objective testing for diagnosis and pepsin detection into the tear and nasal mucosa are needed in order to explore this potential relationship.
Topics: Humans; Lacrimal Duct Obstruction; Laryngitis; Laryngopharyngeal Reflux; Nasolacrimal Duct; Pepsin A
PubMed: 33849761
DOI: 10.1016/j.jvoice.2021.03.010 -
Marine Drugs Feb 2023There is a growing demand for the identification of alternative sources of collagen not derived from land-dwelling animals. The present study explored the use of pepsin-...
There is a growing demand for the identification of alternative sources of collagen not derived from land-dwelling animals. The present study explored the use of pepsin- and acid-based extraction protocols to isolate collagen from the swim bladders of . After extraction, these acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) samples respectively were subjected to spectral analyses and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) characterization, revealing both to be comprised of type I collagen with a triple-helical structure. The imino acid content of these ASC and PSC samples was 195 and 199 residues per 1000 residues, respectively. Scanning electron microscopy demonstrated that samples of freeze-dried collagen exhibited a compact lamellar structure, while transmission electron microscopy and atomic force microscopy confirmed the ability of these collagens to undergo self-assembly into fibers. ASC samples exhibited a larger fiber diameter than the PSC samples. The solubility of both ASC and PSC was highest under acidic pH conditions. Neither ASC nor PSC caused any cytotoxicity when tested in vitro, which met one of the requirements for the biological evaluation of medical devices. Thus, collagen isolated from the swim bladders of holds great promise as a potential alternative to mammalian collagen.
Topics: Animals; Pepsin A; Fish Proteins; Collagen; Collagen Type I; Acids; Perciformes; Solubility; Skin; Mammals
PubMed: 36976208
DOI: 10.3390/md21030159 -
Food & Function Jan 2016The development of in vitro digestion models relies on the availability of in vivo data such as digestive enzyme levels and pH values recorded in the course of meal... (Review)
Review
The development of in vitro digestion models relies on the availability of in vivo data such as digestive enzyme levels and pH values recorded in the course of meal digestion. The variations of these parameters along the GI tract are important for designing dynamic digestion models but also static models for which the choice of representative conditions of the gastric and intestinal conditions is critical. Simulating gastric digestion with a static model and a single set of parameters is particularly challenging because the variations in pH and enzyme concentration occurring in the stomach are much broader than those occurring in the small intestine. A review of the literature on this topic reveals that most models of gastric digestion use very low pH values that are not representative of the fed conditions. This is illustrated here by showing the variations in gastric pH as a function of meal gastric emptying instead of time. This representation highlights those pH values that are the most relevant for testing meal digestion in the stomach. Gastric lipolysis is still largely ignored or is performed with microbial lipases. In vivo data on gastric lipase and lipolysis have however been collected in humans and dogs during test meals. The biochemical characterization of gastric lipase has shown that this enzyme is rather unique among lipases: (i) stability and activity in the pH range 2 to 7 with an optimum at pH 4-5.4; (ii) high tensioactivity that allows resistance to bile salts and penetration into phospholipid layers covering TAG droplets; (iii) sn-3 stereospecificity for TAG hydrolysis; and (iv) resistance to pepsin. Most of these properties have been known for more than two decades and should provide a rational basis for the replacement of gastric lipase by other lipases when gastric lipase is not available.
Topics: Animals; Digestion; Dogs; Gastric Emptying; Humans; Hydrogen-Ion Concentration; Hydrolysis; Intestines; Kinetics; Lipase; Lipolysis; Models, Biological; Models, Molecular; Molecular Structure; Pepsin A; Stomach; Substrate Specificity; Triglycerides
PubMed: 26527368
DOI: 10.1039/c5fo00930h