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EFSA Journal. European Food Safety... Jun 2023The food enzyme containing chymosin (EC 3.4.23.4) and pepsin A (EC 3.4.23.1) is prepared from the abomasum of calves and cows () by Chr. Hansen. The food enzyme is...
The food enzyme containing chymosin (EC 3.4.23.4) and pepsin A (EC 3.4.23.1) is prepared from the abomasum of calves and cows () by Chr. Hansen. The food enzyme is intended to be used in milk processing for cheese production and in milk processing for the production of fermented milk products. As no concerns arise from the animal source of the food enzyme, from its manufacture, and based on the history of safe use and consumption, the Panel considered that toxicological data were unnecessary and an estimation of dietary exposure was not required. A search for the similarity of the amino acid sequences of the two proteins (chymosin and pepsin A) to those of known allergens was made and one match with pig pepsin, a respiratory allergen, was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.
PubMed: 37396876
DOI: 10.2903/j.efsa.2023.8084 -
American Journal of Respiratory and... Dec 2022Primary graft dysfunction (PGD) is the principal cause of early morbidity and mortality after lung transplantation. The lung microbiome has been implicated in later...
Primary graft dysfunction (PGD) is the principal cause of early morbidity and mortality after lung transplantation. The lung microbiome has been implicated in later transplantation outcomes but has not been investigated in PGD. To define the peritransplant bacterial lung microbiome and relationship to host response and PGD. This was a single-center prospective cohort study. Airway lavage samples from donor lungs before organ procurement and recipient allografts immediately after implantation underwent bacterial 16S ribosomal ribonucleic acid gene sequencing. Recipient allograft samples were analyzed for cytokines by multiplex array and pepsin by ELISA. We enrolled 139 transplant subjects and obtained donor lung ( = 109) and recipient allograft ( = 136) samples. Severe PGD (persistent grade 3) developed in 15 subjects over the first 72 hours, and 40 remained without PGD (persistent grade 0). The microbiome of donor lungs differed from healthy lungs, and recipient allograft microbiomes differed from donor lungs. Development of severe PGD was associated with enrichment in the immediate postimplantation lung of oropharyngeal anaerobic taxa, particularly . Elevated pepsin, a gastric biomarker, and a hyperinflammatory cytokine profile were present in recipient allografts in severe PGD and strongly correlated with microbiome composition. Together, immediate postimplantation allograft / ratio, pepsin, and indicator cytokines were associated with development of severe PGD during the 72-hour post-transplantation period (area under the curve = 0.81). Lung allografts that develop PGD have a microbiome enriched in anaerobic oropharyngeal taxa, elevated gastric pepsin, and hyperinflammatory phenotype. These findings suggest a possible role for peritransplant aspiration in PGD, a potentially actionable mechanism that warrants further investigation.
Topics: Humans; Primary Graft Dysfunction; Pepsin A; Prospective Studies; Lung Transplantation; Cytokines; Lung; Inflammation; Allografts; Microbiota
PubMed: 36103583
DOI: 10.1164/rccm.202112-2786OC -
Enzyme and Microbial Technology Nov 2020Pepsin, the archetypal pepsin-like aspartic protease, is irreversibly denatured when exposed to neutral pH conditions whereas renin, a structural homologue of pepsin, is... (Comparative Study)
Comparative Study
Pepsin, the archetypal pepsin-like aspartic protease, is irreversibly denatured when exposed to neutral pH conditions whereas renin, a structural homologue of pepsin, is fully stable and optimally active in the same conditions despite sharing highly similar enzyme architecture. To gain insight into the structural determinants of differential aspartic protease pH stability, the present study used comparative bioinformatic and structural analyses. In pepsin, an abundance of polar and aspartic acid residues were identified, a common trait with other acid-stable enzymes. Conversely, renin was shown to have increased levels of basic amino acids. In both pepsin and renin, the solvent exposure of these charged groups was high. Having similar overall acidic residue content, the solvent-exposed basic residues may allow for extensive salt bridge formation in renin, whereas in pepsin, these residues are protonated and serve to form stabilizing hydrogen bonds at low pH. Relative differences in structure and sequence in the turn and joint regions of the β-barrel and ψ-loop in both the N- and C-terminal lobes were identified as regions of interest in defining divergent pH stability. Compared to the structural rigidity of renin, pepsin has more instability associated with the N-terminus, specifically the B/C connector. By contrast, renin exhibits greater C-terminal instability in turn and connector regions. Overall, flexibility differences in connector regions, and amino acid composition, particularly in turn and joint regions of the β-barrel and ψ-loops, likely play defining roles in determining pH stability for renin and pepsin.
Topics: Amino Acid Sequence; Amino Acids; Animals; Computational Biology; Enzyme Stability; Humans; Hydrogen Bonding; Hydrogen-Ion Concentration; Pepsin A; Protein Structure, Tertiary; Protein Unfolding; Renin; Sequence Alignment; Solvents
PubMed: 33051007
DOI: 10.1016/j.enzmictec.2020.109632 -
Histochemistry and Cell Biology Jun 2023This study compares three different pretreatment protocols for the immunohistochemical detection of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in...
This study compares three different pretreatment protocols for the immunohistochemical detection of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in nuclear DNA. The human biological samples analyzed included formalin-fixed and paraffin-embedded (FFPE) normal squamous epithelium, ethanol-fixed cultured cells, and metaphase chromosomes. The antigen retrieval methods included low pH Citrate and high pH Tris-ethylenediaminetetraacetic acid (EDTA) protocols, as well as a method using Pepsin pretreatment combined with HCl for DNA denaturation. A gradual increase in the detection levels of 5-mC and 5-hmC was observed when going from Citrate via Tris/EDTA to Pepsin/HCl retrieval. While the Citrate retrieval protocol was the least efficient for the detection of 5-mC and 5-hmC, it did preserve nuclear morphology and enabled visualization of differences in intra- and internuclear distribution patterns in tissue and cell culture samples by single- and double-fluorescence detection. Quantification of (hydroxy)methylation levels in FFPE material demonstrated a significant heterogeneity and differences in 5-mC and 5-hmC levels within and between nuclei in the different compartments of normal squamous epithelium. It was concluded that immunohistochemical detection of 5-mC and 5-hmC enables the correlation of these DNA modifications with histomorphological features in heterogeneous tissues, but this is influenced by different pretreatment protocols that must be carefully chosen to allow an appropriate interpretation of these epigenetic switches.
Topics: Humans; Edetic Acid; Pepsin A; 5-Methylcytosine; Epigenesis, Genetic; DNA; DNA Methylation; Antigens; Carcinoma, Squamous Cell; Citrates; Cytosine
PubMed: 37010548
DOI: 10.1007/s00418-023-02187-4 -
Journal of Agricultural and Food... Mar 2024Coffee is one of the most popular beverages around the world and its consumption contributes to the daily intake of dietary melanoidins. Despite the emerging...
Coffee is one of the most popular beverages around the world and its consumption contributes to the daily intake of dietary melanoidins. Despite the emerging physiological role of food melanoidins, their effect on digestive processes has not been studied so far. In this study, the activity of the gastrointestinal enzymes pepsin and trypsin was investigated in the presence of water-soluble coffee melanoidins. The gastric enzyme pepsin is only slightly affected, whereas the intestinal enzyme trypsin is severely inhibited by coffee melanoidins. The intestinal digestibility of casein was significantly inhibited by coffee melanoidins at a concentration achievable by regular coffee consumption. The inhibition of proteolytic enzymes by coffee melanoidins might decrease the nutritional value of dietary proteins.
Topics: Coffee; Pepsin A; Peptide Hydrolases; Trypsin; Dietary Proteins; Polymers
PubMed: 38456211
DOI: 10.1021/acs.jafc.3c09654 -
Journal of Trace Elements in Medicine... Jul 2021The paper presents a study on the influence of different lithium carbonate and lithium citrate concentration on proteolytic enzymes, namely pepsin and trypsin, in vitro....
BACKGROUND
The paper presents a study on the influence of different lithium carbonate and lithium citrate concentration on proteolytic enzymes, namely pepsin and trypsin, in vitro. Lithium can directly affect enzyme activity. Its influence on many bodily functions in both ill and healthy people has been proven.
METHODS
To assess the influence of Li ions concentration and the substrate/enzyme ratio on pepsin and trypsin activity in vitro, 60 factorial experiments were conducted (each repeated 30 times).
MAIN FINDINGS
For both enzymes, statistically significant changes in their activity under the influence of lihium carbonate and lithium citrate were observed. The biggest increase in enzyme activity reached even 198.6 % and the largest decrease in enzyme activity reached about 50 %.
CONCLUSIONS
The study shows that both organic and inorganic forms of lithium salts cause changes in the activity of digestive enzymes. Different concentrations of lithium carbonate and lithium citrate stimulate or inhibit the activity of trypsin and pepsin.
Topics: Citrates; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Ions; Lithium Carbonate; Pepsin A; Trypsin
PubMed: 33915410
DOI: 10.1016/j.jtemb.2021.126763 -
Medicine May 2021The aim of this study is to explore the relationship between gastroesophageal reflux disease (GERD) and vocal fold polyps (VFPs).This is a Case-Control study and was... (Observational Study)
Observational Study
The aim of this study is to explore the relationship between gastroesophageal reflux disease (GERD) and vocal fold polyps (VFPs).This is a Case-Control study and was performed with the help of The Second Affiliated Hospital of Chongqing Medical University.Twenty-seven patients with VFP and 20 controls without VFP were recruited between May and October 2018. All the subjects underwent a saliva pepsin test, completed the GerdQ questionnaire and 24-hour multichannel intraluminal impedance with pH (24-h MII-pH) monitoring. Twenty-five resected VFP specimens were examined with immunohistochemical (IHC) and double immunofluorescence (IF) staining.The incidence of GERD in the VFP group was significantly higher than that in the control group (P = .003). Patients with VFP had significantly higher GerdQ scores, pepsin concentrations, and pepsin-positive rates (P < .05). Moreover, the number of proximal and upright reflux events was significantly higher in the VFP group (P < .05). The pepsin concentration in saliva showed a significant positive correlation with the pepsin levels in tissues (r2 = 0.50, P = .011). Pepsin and TGF-β1-positive cells were colocalized with CD45RO-positive cells. IHC staining showed that the majority of VFP patients had a positive expression of pepsin (20/25, 80%) and pepsin-positive cells were found in both the squamous epithelium and mesenchymal tissues. IHC staining of TGF-β1 in VFP revealed findings similar to those of pepsin staining.GERD is an important risk factor for VFP. Pepsin may promote the aggregation of immune cells, increase the local cytokines, and promote inflammatory reaction, suggesting a potential new pathogenesis for VFP. The saliva pepsin test is a reliable method for GERD diagnosis.
Topics: Adult; Aged; Case-Control Studies; Esophageal pH Monitoring; Female; Gastroesophageal Reflux; Humans; Incidence; Male; Middle Aged; Pepsin A; Polyps; Prospective Studies; Respiratory Mucosa; Risk Factors; Saliva; Vocal Cords
PubMed: 34011039
DOI: 10.1097/MD.0000000000025787 -
Biosensors Nov 2022Instead of molecularly imprinting a whole protein molecule, imprinting protein epitopes is gaining popularity due to cost and solubility issues. Belonging to the matrix...
Instead of molecularly imprinting a whole protein molecule, imprinting protein epitopes is gaining popularity due to cost and solubility issues. Belonging to the matrix metalloproteinase protein family, MMP-1 is an interstitial collagenase that degrades collagen and may be involved in cell migration, cell proliferation, the pro-inflammatory effect, and cancer progression. Hence, it can serve as a disease protein biomarker and thus be useful in early diagnosis. Herein, epitopes of MMP-1 were identified by screening its crystal structure. To identify possible epitopes for imprinting, MMP-1 was cleaved in silico with trypsin, pepsin at pH = 1.3, and pepsin at pH > 2.0 using Peptide Cutter, generating peptide fragments containing 8 to 12 amino acids. Five criteria were applied to select the peptides most suitable as potential epitopes for MMP-1. The triphenylamine rhodanine-3-acetic acid (TPARA) functional monomer was synthesized to form a stable pre-polymerization complex with a selected template epitope. The complexed functional monomer was then copolymerized with 3,4-ethoxylenedioxythiophene (EDOT) using potentiodynamic electropolymerization onto indium−tin−oxide (ITO) electrodes. The composition of the molecularly imprinted poly(TPARA-co-EDOT) (MIP) was optimized by maximizing the film’s electrical conductivity. Cyclic voltammetry was used to determine MMP-1 concentration in the presence of the Fe(CN)63−/Fe(CN)64− redox probe actuating the “gate effect.” A calibration curve was constructed and used to determine the usable concentration range and the limit of detection as ca. 0.001 to 10.0 pg/mL and 0.2 fg/mL MMP-1, respectively. Finally, the MMP-1 concentration in the A549 human lung (carcinoma) culture medium was measured, and this determination accuracy was confirmed using an ELISA assay.
Topics: Humans; Molecular Imprinting; Matrix Metalloproteinase 1; Epitopes; Polymers; Pepsin A; Peptides; Poly A
PubMed: 36421137
DOI: 10.3390/bios12111018 -
Diseases of the Esophagus : Official... Apr 2021Uncertain diagnostic performance has limited clinical adoption of salivary pepsin, a noninvasive diagnostic tool for gastroesophageal reflux disease (GERD). This study...
Uncertain diagnostic performance has limited clinical adoption of salivary pepsin, a noninvasive diagnostic tool for gastroesophageal reflux disease (GERD). This study aimed to assess diagnostic performance of salivary pepsin, and test validity of thresholds in an external cohort of patients with or without GERD. This two-phase prospective study conducted at two centers enrolled adult asymptomatic volunteers, patients with symptoms of GERD undergoing reflux monitoring, and patients with Barrett's esophagus (BE). Fasting saliva samples were processed for pepsin concentration using Peptest. Phase 1 compared pepsin concentration between No GERD (volunteers/functional heartburn) and GERD (erosive reflux disease/nonerosive reflux disease (NERD)/BE). Phase 2 tested validity of the diagnostic thresholds identified from Phase 1 among external functional heartburn and NERD cohorts. Of 243 enrolled subjects, 156 met inclusion criteria. Phase 1 (n = 114): Pepsin concentrations were significantly higher in GERD (n = 84) versus No GERD (n = 30) (73.8 ng/mL vs. 21.1 ng/mL; P < 0.001). Area under the curve for pepsin concentration was 0.74 (95% CI 0.65, 0.83). A salivary pepsin threshold of 24.9 ng/mL optimized the true negative rate and 100.0 ng/mL optimized the true positive rate. Phase 2 (n = 42): Pepsin concentrations were significantly higher in NERD (n = 22) versus Functional Heartburn (n = 20) (176.0 ng/mL vs. 53.3 ng/mL, P < 0.001). Applying Phase 1 thresholds in this external cohort, salivary pepsin 24.9 ng/mL was 86% sensitive (64%, 97%) and 100.0 ng/mL was 72% specific for distinguishing NERD from functional heartburn. Given modest sensitivity and specificity for GERD, salivary pepsin may have clinical utility as a noninvasive office based diagnostic screening tool for GERD.
Topics: Adult; Gastroesophageal Reflux; Heartburn; Humans; Pepsin A; Prospective Studies; Saliva
PubMed: 33180095
DOI: 10.1093/dote/doaa117 -
Otolaryngology--head and Neck Surgery :... Mar 2022To evaluate the necessity of multiple salivary pepsin tests within a day when diagnosing laryngopharyngeal reflux.
OBJECTIVES
To evaluate the necessity of multiple salivary pepsin tests within a day when diagnosing laryngopharyngeal reflux.
STUDY DESIGN
Prospective cohort study.
SETTING
Tertiary hospitals.
METHODS
A total of 138 patients with signs and/or symptoms associated with laryngopharyngeal reflux were included. Salivary pepsin was detected on the day of 24-hour pH monitoring, and the results of salivary pepsin detected once in the morning and multiple times in 1 day were compared with the results of pH monitoring.
RESULTS
Among the 138 patients, pH monitoring results were positive in 112. Salivary pepsin was positive in 47 cases in the morning, which was not consistent with the results of pH monitoring (kappa value = 0.117). With the pH monitoring results as the standard, the salivary pepsin detected once in the morning had a sensitivity of 38.4% (43/112) and a specificity of 84.6% (22/26) for the diagnosis of laryngopharyngeal reflux. When salivary pepsin was detected multiple times per day, 102 patients tested positive. The consistency with pH monitoring was moderate (kappa value = 0.587). The sensitivity was 86.6% (97/112), and the specificity was 80.8% (21/26). Of the 97 patients with positive results from pH monitoring and salivary pepsin detected multiple times a day, 54 had negative findings for a single detection in the morning, indicating that 55.7% (54/97) of the true positive cases were missed.
CONCLUSION
Although a single detection of salivary pepsin in the morning is more economical, the sensitivity is too low, and it is necessary to detect it multiple times a day.
Topics: Esophageal pH Monitoring; Humans; Laryngopharyngeal Reflux; Pepsin A; Prospective Studies; Saliva
PubMed: 34253110
DOI: 10.1177/01945998211026837