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Scientific Reports Apr 2022Combined use of fibrin glue and polyglycolic acid (PGA) sheets has attracted attention as a preventive measure for complications associated with endoscopic submucosal...
Combined use of fibrin glue and polyglycolic acid (PGA) sheets has attracted attention as a preventive measure for complications associated with endoscopic submucosal dissection. However, fibrin glue is a protein that may be dissolved by gastric acid. We evaluated the effect of artificial gastric acid on fibrin clot. The dissolution time of three layers of fibrin glue with PGA sheets was measured in five groups (pH 1.2, 2.0, 4.0, 5.5, and 6.0 with pepsin). Measurements of three samples per group were made. The mean number of the remaining layers at each measurement point was observed for 168 h. The time to complete dissolution of the three layers of fibrin gel in the three samples was 2.5 h at pH 1.2, 5 h at pH 2.0, 24 h at pH 4.0, and 48 h and 6 h at pH 5.5. In order to maintain fibrin glue in the stomach for a long period, there was a need to avoid pepsin activation secondary to acidification of gastric juice. The use of strong antacids is recommended.
Topics: Fibrin Tissue Adhesive; Hydrogen-Ion Concentration; Pepsin A; Polyglycolic Acid; Solubility; Stomach; Tissue Adhesives
PubMed: 35484272
DOI: 10.1038/s41598-022-10968-5 -
Biosensors Mar 2022A new preparation route for high-luminescent blue-emission pepsin copper nanoclusters (Pep-CuNCs) is introduced in this work. The synthesized nanoclusters are based on a...
A new preparation route for high-luminescent blue-emission pepsin copper nanoclusters (Pep-CuNCs) is introduced in this work. The synthesized nanoclusters are based on a pepsin molecule, which is a stomach enzyme that works to digest proteins that exist in undigested food. Here, we have developed an eco-friendly technique through microwave-assisted fast synthesis. The resulting copper nanoclusters (CuNCs) exhibit significant selectivity towards Pb(II) ions. The pepsin molecule was utilized as a stabilizer and reducing agent in the production procedure of Pep-CuNCs. The characteristics of the resulting Pep-CuNCs were studied in terms of size, surface modification, and composition using various sophisticated techniques. The CuNCs responded to Pb(II) ions through the fluorescence quenching mechanism of the CuNCs' fluorescence. Thus, great selectivity of Pep-CuNCs towards Pb(II) ions was observed, allowing sensitive determination of this metal ion at lab-scale and in the environment. The CuNCs have detection limits for Pb(II) in very tenuous concentration at a nanomalar scale (11.54 nM). The resulting Pep-CuNCs were utilized significantly to detect Pb(II) ions in environmental samples. Additionally, the activity of Pep-CuNCs on different human tumor cell lines was investigated. The data for the observed behavior indicate that the Pep-CuNCs displayed their activity against cancer cells in a dose dependent manner against most utilized cancer cell lines.
Topics: Copper; Fluorescent Dyes; Humans; Ions; Lead; Limit of Detection; Metal Nanoparticles; Pepsin A; Spectrometry, Fluorescence
PubMed: 35448257
DOI: 10.3390/bios12040197 -
Allergology International : Official... Oct 2022Early food introduction induces tolerance, but epicutaneous exposure, especially via eczema lesions, promotes IgE sensitization. Aiming for safe and effective primary...
BACKGROUND
Early food introduction induces tolerance, but epicutaneous exposure, especially via eczema lesions, promotes IgE sensitization. Aiming for safe and effective primary prevention of egg allergy, we examined several protease-digested egg-white (EW) products for three properties: 1) induction of oral tolerance that prevents IgE sensitization, 2) weak IgE binding that can prevent allergic reactions even in IgE-sensitized mice, and 3) minimal epicutaneous IgE sensitization even when in contact with inflamed skin.
METHODS
Heated EW was digested with several proteases under optimal conditions. First, three-week-old BALB/c female mice were intragastrically administered EW or each protease-digested EW product, followed by intraperitoneal ovalbumin (OVA) or ovomucoid (OVM) injection with alum. Serum OVA- and OVM-specific IgE titers were measured. Second, six-week-old mice were sensitized with OVA/OVM, and the rectal temperature was measured after intraperitoneal administration of EW or each protease-digested EW. Third, EW or each protease-digested EW product was applied to the tape-stripped skin for 3 days/week for 3 weeks. Serum OVA- and OVM-specific IgE titers were measured.
RESULTS
Orally administered pepsin-digested EW product (PDEW) and Thermoase PC10F-digested EW product (TDEW) significantly suppressed OVA-/OVM-specific IgE production. Neither product elicited a body temperature decline (anaphylaxis) in OVA-/OVM-sensitized mice. Serum OVA-/OVM-specific IgE levels were significantly lower in mice epicutaneously exposed to PDEW or TDEW than in EW-exposed mice.
CONCLUSIONS
Two protease-digested EWs showed potential as optimal EW products for early introduction for primary prevention of egg allergy.
Topics: Allergens; Animals; Egg Hypersensitivity; Eggs; Female; Immunoglobulin E; Mice; Mice, Inbred BALB C; Ovalbumin; Ovomucin; Pepsin A; Peptide Hydrolases
PubMed: 35443911
DOI: 10.1016/j.alit.2022.03.006 -
European Journal of Hospital Pharmacy :... Mar 2023
The PEPSIN project: design and validation of a self-administered questionnaire for the assessment of equivalence between pens and prefilled syringes in patients on subcutaneous biological drugs.
Topics: Humans; Pepsin A; Syringes; Medication Errors
PubMed: 35273003
DOI: 10.1136/ejhpharm-2022-003273 -
Molecules (Basel, Switzerland) Feb 2022In this meta-analysis, we collected 58 publications spanning the last seven decades that reported static in vitro protein gastric digestion results. A number of...
In this meta-analysis, we collected 58 publications spanning the last seven decades that reported static in vitro protein gastric digestion results. A number of descriptors of the pepsinolysis process were extracted, including protein type; pepsin activity and concentration; protein concentration; pH; additives; protein form (e.g., 'native', 'emulsion', 'gel', etc.); molecular weight of the protein; treatment; temperature; and half-times (HT) of protein digestion. After careful analysis and the application of statistical techniques and regression models, several general conclusions could be extracted from the data. The protein form to digest the fastest was 'emulsion'. The rate of pepsinolysis in the emulsion was largely independent of the protein type, whereas the gastric digestion of the native protein in the solution was strongly dependent on the protein type. The pepsinolysis was shown to be strongly dependent on the structural components of the proteins digested-specifically, β-sheet-inhibited and amino acid, leucine, methionine, and proline-promoted digestion. Interestingly, we found that additives included in the digestion mix to alter protein hydrolysis had, in general, a negligible effect in comparison to the clear importance of the protein form or additional treatment. Overall, the findings allowed for the targeted creation of foods for fast or slow protein digestion, depending on the nutritional needs.
Topics: Animals; Dietary Proteins; Digestion; Emulsions; Food Analysis; Hydrogen-Ion Concentration; Hydrolysis; Milk; Pepsin A; Protein Hydrolysates
PubMed: 35209049
DOI: 10.3390/molecules27041260 -
Bosnian Journal of Basic Medical... Jul 2022Obstructive sleep apnoea (OSA) and laryngopharyngeal reflux disease (LPR) are two common diseases that lower patients' quality of life. OSA is defined by cyclic events...
Obstructive sleep apnoea (OSA) and laryngopharyngeal reflux disease (LPR) are two common diseases that lower patients' quality of life. OSA is defined by cyclic events of airflow obstruction that occur during sleep, while LPR is characterized by upper airway inflammatory signs and symptoms due to the return of gastroduodenal gaseous and liquid elements. pH-metry is the gold standard in LPR diagnosis, but considering its invasiveness among other negative traits, questionnaires that catalog symptoms and signs of the disease such as Reflux Symptoms Index (RSI) and Reflux Finding Score (RFS) are preferred. Moreover, LPR can be evaluated by testing the presence of pepsin in tears, and Narrow Band Imaging (NBI) has been introduced for the early diagnosis of larynx oncological disease. This paper aims to test whether LPR is more frequent in OSA patients than in control ones, performing a non-invasive protocol composed of RSI, RFS test (with light vs. NBI techniques), followed by pepsin detection in tears. 68 LPR patients were enrolled in the study (45 with OSA and 23 without OSA). A strong linear relationship between Apnea-Hypopnea Index (AHI) and Oxygen Desaturation Index (ODI) was found, and patients who presented pepsin in tears had higher values of AHI and ODI in comparison to patients without it. Pathological RFS and NBI showed higher values of AHI and ODI in comparison to the control group. Furthermore, pathological RSI showed higher values of AHI and ODI in comparison to the control group. In conclusion, this diagnostic combined non-invasive protocol may be a good method to perform an early diagnosis of LPR.
Topics: Humans; Laryngopharyngeal Reflux; Narrow Band Imaging; Pepsin A; Quality of Life; Sleep Apnea, Obstructive; Tears
PubMed: 35150480
DOI: 10.17305/bjbms.2021.6712 -
Journal of Chemical Information and... Feb 2022The flexibility of β hairpin structure known as the flap plays a key role in catalytic activity and substrate intake in pepsin-like aspartic proteases. Most of these...
The flexibility of β hairpin structure known as the flap plays a key role in catalytic activity and substrate intake in pepsin-like aspartic proteases. Most of these enzymes share structural and sequential similarity. In this study, we have used apo Plm-II and BACE-1 as model systems. In the apo form of the proteases, a conserved tyrosine residue in the flap region remains in a dynamic equilibrium between the normal and flipped states through rotation of the χ and χ angles. Independent MD simulations of Plm-II and BACE-1 remained stuck either in the normal or flipped state. Metadynamics simulations using side-chain torsion angles (χ and χ of tyrosine) as collective variables sampled the transition between the normal and flipped states. Qualitatively, the two states were predicted to be equally populated. The normal and flipped states were stabilized by H-bond interactions to a tryptophan residue and to the catalytic aspartate, respectively. Further, mutation of tyrosine to an amino-acid with smaller side-chain, such as alanine, reduced the flexibility of the flap and resulted in a flap collapse (flap loses flexibility and remains stuck in a particular state). This is in accordance with previous experimental studies, which showed that mutation to alanine resulted in loss of activity in pepsin-like aspartic proteases. Our results suggest that the ring flipping associated with the tyrosine side-chain is the key order parameter that governs flap dynamics and opening of the binding pocket in most pepsin-like aspartic proteases.
Topics: Aspartic Acid Endopeptidases; Catalysis; Pepsin A
PubMed: 35138093
DOI: 10.1021/acs.jcim.1c00840 -
International Journal of Biological... Apr 2022Among the matrices for enzyme immobilization, activated carbon has been standing out in immobilization processes due to its properties and to its characteristics that...
Among the matrices for enzyme immobilization, activated carbon has been standing out in immobilization processes due to its properties and to its characteristics that provide superficial modification by inserting new functional groups capable of binding the enzymes forming covalent bonds. In this study the effect of different modification methods of activated carbon (functionalization with genipin, metallization, metallization in the presence of chelating agent, and functionalization with glutaraldehyde) on efficiency of pepsin immobilization was evaluated. The effect of immobilization pH and the reaction medium on hydrolysis activity of bovine casein was also evaluated. The functionalization of activated carbon using iron ions allowed an immobilization capacity of 98.93 mg·g, with immobilization efficiency greater than 99%, and enzyme activity of 2.30 U, which was higher than the other modifications, and closer to the enzyme in the native form activity (3.32 U). In general, the carbon surface modifications were responsible for forming more stable bonds between support and enzyme, improving its proteolytic activity (from 1.84 to 2.30 U) when compared to traditional immobilization methods by adsorption and covalent binding using glutaraldehyde (from 1.04 to 1.1 U).
Topics: Adsorption; Animals; Cattle; Enzyme Stability; Enzymes, Immobilized; Glutaral; Hydrogen-Ion Concentration; Pepsin A
PubMed: 35090943
DOI: 10.1016/j.ijbiomac.2022.01.135 -
European Archives of... Jun 2022To explore the role played by Glut-1 and H/K-ATPase in pepsin-induced, mouse laryngeal epithelial proliferation, growth, and development.
PURPOSE
To explore the role played by Glut-1 and H/K-ATPase in pepsin-induced, mouse laryngeal epithelial proliferation, growth, and development.
METHODS
We established a mouse model of laryngopharyngeal reflux and measured Glut-1 and H/K-ATPase expression levels in mouse laryngeal epithelium treated with artificial gastric juice containing pepsin.
RESULTS
Artificial pepsin-containing gastric juice induced significant hyperplastic changes in mouse laryngeal epithelium compared to control mice at 15, 30, and 45 days. Inhibition of Glut-1 expression by 2-DG significantly suppressed such hyperplasia compared to mice exposed to artificial gastric juice containing pepsin at 15, 30, and 45 days. After treatment with pepsin-containing artificial gastric juice, RT-PCR and Western blotting showed that the levels of Glut-1 and H/K-ATPase α, β increased significantly.
CONCLUSIONS
Pepsin-containing artificial gastric juice promoted mouse laryngeal epithelial hyperplasia associated with abnormal expression of Glut-1 and H/K-ATPase α, β.
Topics: Adenosine Triphosphatases; Animals; Humans; Hyperplasia; Laryngeal Mucosa; Laryngopharyngeal Reflux; Mice; Pepsin A
PubMed: 35083516
DOI: 10.1007/s00405-021-07221-6 -
Journal of Dairy Science Feb 2022Hydrolysis-induced coagulation of casein micelles by pepsin occurs during the digestion of milk. In this study, the effect of pH (6.7-5.3) and pepsin concentration...
Hydrolysis-induced coagulation of casein micelles by pepsin occurs during the digestion of milk. In this study, the effect of pH (6.7-5.3) and pepsin concentration (0.110-2.75 U/mL) on the hydrolysis of κ-casein and the coagulation of the casein micelles in bovine skim milk was investigated at 37°C using reverse-phase HPLC, oscillatory rheology, and confocal laser scanning microscopy. The hydrolysis of κ-casein followed a combined kinetic model of first-order hydrolysis and putative pepsin denaturation. The hydrolysis rate increased with increasing pepsin concentration at a given pH, was pH dependent, and reached a maximum at pH ∼6.0. Both the increase in pepsin concentration and decrease in pH resulted in a shorter coagulation time. The extent of κ-casein hydrolysis required for coagulation was independent of the pepsin concentration at a given pH and, because of the lower electrostatic repulsion between para-casein micelles at lower pH, decreased markedly from ∼73% to ∼33% when pH decreased from 6.3 to 5.3. In addition, the rheological properties and the microstructures of the coagulum were markedly affected by the pH and the pepsin concentration. The knowledge obtained from this study provides further understanding on the mechanism of milk coagulation, occurring at the initial stage of transiting into gastric conditions with high pH and low pepsin concentration.
Topics: Animals; Caseins; Cattle; Hydrogen-Ion Concentration; Hydrolysis; Kinetics; Micelles; Milk Proteins; Pepsin A; Rheology
PubMed: 34998540
DOI: 10.3168/jds.2021-21177