Search Results (165)

Carboxypeptidase A4 (CPA4) is an exopeptidase that cleaves peptide bonds at the C-terminal domain within peptides and proteins. It preferentially cleaves peptides with terminal aromatic or branched chain amino acid residues such as phenylalanine, tryptophan, or leucine. CPA4 was first discovered in prostate cancer cells, but it is now known to be expressed in various tissues throughout the body. Its physiologic expression is governed by latexin, a noncompetitive endogenous inhibitor of CPA4. Nevertheless, the overexpression of CPA4 has been associated with the progression and aggressiveness of many malignancies, including prostate, pancreatic, breast and lung cancer, to name a few. CPA4’s role in cancer has been attributed to its disruption of many cellular signaling pathways, e.g., PI3K-AKT-mTOR, STAT3-ERK, AKT-cMyc, GPCR, and estrogen signaling. The dysregulation of these pathways by CPA4 could be responsible for inducing epithelial--mesenchymal transition (EMT), tumor invasion and drug resistance. Although CPA4 has been found to regulate cancer aggressiveness and poor prognosis, no comprehensive review summarizing the role of CPA4 in cancer is available so far. In this review, we provide a brief description of peptidases, their classification, history of CPA4, mechanism of action of CPA4 as a peptidase, its expression in various tissues, including cancers, its role in various tumor types, the associated molecular pathways and cellular processes. We further discuss the limitations of current literature linking CPA4 to cancers and challenges that prevent using CPA4 as a biomarker for cancer aggressiveness and predicting drug response and highlight a number of future strategies that can help to overcome the limitations. Full article

Following lung cancer, prostate cancer is the leading cause of cancer death in men. High-risk localized tumor burden or metastatic disease often progresses, refractory to initial treatment regimens. There is ongoing development of technology to appropriately identify high-risk patients, stage them correctly, and offer appropriate treatments to obtain the best clinical outcomes. Prostate cancer-specific membrane antigen (PSMA) is a transmembrane glutamate carboxypeptidase, which helps regulate folate absorption, and its overexpression is pathologically directly proportional and associated with prostate cancer. Increased PSMA expression is a known independent risk factor for poorer survival, and most metastatic lesions in CRPC are PSMA positive. Over the last decade, several PSMA-based PET radiopharmaceuticals have demonstrated superior sensitivities and specificities compared to traditional imaging methods. These outcomes have been demonstrated by several large clinical trials. As the data emerges, these diagnostics are being integrated into standard of care protocol to facilitate nuanced identification of malignant lesions. PSMA is also being targeted through several therapeutics, including radioligands and immunotherapies such as CAR-T, BiTEs, and ADCs. This review will discuss the landscape of PSMA-based theranostics in the context of prostate cancer. Full article

Fruit yield and quality improvement are challenges for researchers and farmers. This study reveals that the main fruit traits of blueberry (Vaccinium ashei ‘Bluegem’) were significantly improved after hydrogen (H₂)-based irrigation, assessed by the increased single fruit weight (14.59 ± 6.66%) and fruit equatorial diameter (4.19 ± 2.39%), decreased titratable acidity, increased solid–acid and sugar–acid ratios. The enhancement of fruit quality was confirmed by the increased total volatiles, vitamin C contents, and antioxidant capacity. Using weighted protein co-expression network analysis (WPCNA), proteomic interrogation revealed that serine carboxypeptidase-like proteins I/II (SCPLI/II), ADP ribosylation factor 1/2 (ARF1/2), and UDP-glucosyltransferase 85A (UGT85A) might be functionally associated with the increased fruit weight and size driven by H₂. Reduced organic acid accumulation was caused by the regulation of the specific enzymes involved in sucrose metabolism (e.g., α-amylase, endoglucanase, β-glucosidase, etc.). H₂ regulation of fatty acid degradation (e.g., acyl CoA oxidase 1 (ACX1), acetyl CoA acyltransferase 1 (ACAA1), etc.) and phenylpropanoid metabolism were used to explain the improved fruit aroma and anthocyanin accumulation. Meanwhile, the upregulated heat shock protein 20/70 matched with the enhanced antioxidant activity. Together, this study provides a novel approach for yield and quality improvement in horticultural crops. Full article

Background: Plastic is one of the most versatile and widely used materials, but the environmental accumulation of nanoplastics (NPs) poses a risk to human health. Preclinical studies have verified that the liver is one of the main organs susceptible to NPs. Biobran/MGN-3, an arabinoxylan from rice bran, has been shown to have hepatoprotective effects; here, we show Biobran’s ability to alleviate polyethylene nanoplastics (PE-NPs)-induced liver cell toxicity by reversing apoptosis and restoring G2/M cell arrest in mouse liver cells (BNL CL.2). Methods: Toxicological effects were measured using the sulforhodamine B (SRB) assay for cell viability and flow cytometry for cell cycle analysis and apoptosis. An in silico study was also used to demonstrate the docking of PE-NPs to pro-inflammatory mediator proteins (IL-6R, IL-17R, CD41/CD61, CD47/SIRP), cell cycle regulators (BCL-2, c-Myc), as well as serine carboxypeptidase, which is an active ingredient of Biobran. Results: Exposing liver cells to PE-NPs caused a significant decrease in cell viability, with an IC50 value of 334.9 ± 2.7 µg/mL. Co-treatment with Biobran restored cell viability to normal levels, preserving 85% viability at the highest concentration of PE-NPs. Additionally, total cell death observed after exposure to PE-NPs was reduced by 2.4-fold with Biobran co-treatment. The G2/M arrest and subsequent cell death (pre-G0 phase) induced by PE-NPs were normalized after combined treatment. The in silico study revealed that Biobran blocks the nucleophilic centers of PE-NPs, preventing their interaction with pro-inflammatory mediators and cell cycle regulators. Conclusions: These findings highlight the potential use of Biobran as a hepatoprotector against NP toxicity. Full article

Two enzymatic assays, based on release of p-nitroaniline and its spectrophotometric detection at 405 nm, were used to screen lager and ale brewing yeasts for carboxypeptidase and γ-glutamyltranspeptidase activity. Both activities were found in all the investigated yeasts and did not significantly distinguish Saccharomyces cerevisiae from S. pastorianus species. Large between-strain differences were measured for both carboxypeptidase (from 1.61 A/h for BRAS-45 to 41.71 A/h for E-30) and γ-glutamyltranspeptidase (from 1.26 A/h for US-05 to 48.72 A/h for S-33). No correlation was found between either enzymatic activity and the previously published ability of Saccharomyces yeasts to degrade glutathionyl or γ-GluCys- precursors to free polyfunctional thiols. Only for fermentation at lower temperatures does carboxypeptidase activity seem relevant for identifying the most interesting candidates. Measuring transport efficiency and β-lyase activities individually on the three possible intermediates emerges here as more promising for future flavor potential screening. Full article

β-Lactamase/transpeptidase-like superfamily proteins are serine proteases that use the Ser–Lys catalytic dyad to carry out their biological functions. Here, we investigate the three known families of β-lactamase/transpeptidase-like superfamily proteins, β-lactamase/D-Ala carboxypeptidase, glutaminase, and Dac-like, and describe the structural catalytic cores that govern the catalytic residues in these proteins. We show that the structural catalytic core of these proteins is a combination of three zones, the mutual three-dimensional arrangement of which correspondingly determines their belonging to one of seven and twenty-four established groups and subgroups. Full article

Human angiotensin-I-converting enzyme (ACE) is involved in vasoregulation, inflammation, and neurodegenerative disorders. The enzyme is formed of two domains; the C-domain (cACE) is primarily involved in blood pressure regulation, whereas the N-domain (nACE) is strongly linked to fibrosis; hence, designing domain-specific inhibitors could make a difference between treating one condition without having a negative effect on another. AnCE (a close homologue of ACE) is derived from Drosophila melanogaster and has a high similarity specifically to cACE. Due to high similarity and ease of crystallisation, AnCE has been chosen as a model protein for ACE studies and for the design of ACE inhibitors. In this study, enzyme kinetic assays and X-ray crystallography techniques revealed the significance of using dipeptides as selective inhibitors for AnCE and how this knowledge could be applied to cACE and nACE. All the dipeptides tested in this study were shown to bind AnCE in two distinct locations, i.e., the non-prime and prime subsites. It was found that a hydrophobic residue at the S1 and S1′ subsites, with a tryptophan at the S2 and S2′ subsites, showed highest affinity towards AnCE. It was also observed that a key pocket within the S2′ subsite had a major influence on the binding orientation within the prime subsites and could potentially explain ACE’s dipeptidyl carboxypeptidase activity. Importantly these dipeptides are found in functional foods, making them potentially available from diets. Knowledge of the dipeptide binding presented here could aid in the development of ACE domain-specific inhibitors. Full article

The impact of exercise on human metabolism has been extensively studied, yet limited research exists on the effects of high-intensity racing on equine metabolism. The aim of this study was to screen the effect of a 5000 m race on lipids and proteins in the plasma of Yili horses for the breeding of racehorses. Blood samples were collected from the top three finishers, and lipidomics and proteomics analyses were performed. Lipidomic analysis identified 10 differential lipids. Compared to pre-race levels, phosphatidylethanolamine (18:0/16:0) (PE (18:0/16:0)) and phosphatidylcholine (18:0/18:2) (PC (18:0/18:2)) were significantly upregulated, while triglyceride (26:4/29:4) (TG (26:4/29:4)) and phosphatidylcholine (46:14CHO) (PC (46:14CHO)) were notably downregulated. These lipids were primarily associated with the regulation of lipolysis in adipocytes and glycerolipid metabolism pathways. Proteomic analysis revealed 79 differentially expressed proteins. Post-race, proteasome subunits (alpha type_2, alpha type_5 isoform X1, alpha type_6, and beta type_2), carboxypeptidase E, and S-phase kinase-associated protein 1 showed significant downregulation. These proteins were primarily involved in the cellular catabolic process (Gene Ontology term) and pathways related to the proteasome and type I diabetes mellitus (Kyoto Encyclopedia of Genes and Genomes terms). Correlation analysis indicated a significant positive correlation between proteasome subunits (alpha type_2 and beta type_2) and PC (18:0/18:2), while a significant negative correlation was found with PC (46:14CHO). Conversely, S-phase kinase-associated protein 1, along with proteasome subunits (alpha type_5 isoform X1 and alpha type_6), exhibited a significant negative correlation with PE (18:0/16:0) and a positive correlation with TG (26:4/29:4). In conclusion, Yili horses may sustain energy balance and physiological equilibrium during racing by suppressing protein degradation and optimizing lipid metabolism. The differentially expressed substances identified could serve as key biomarkers for assessing exercise load in horses. Full article

Background: LR18 is an α₋helical AMP with high antimicrobial activity, low hemolytic activity, and low cytotoxicity. However, the susceptibility to degradation of the peptidase enzyme and a short half-life hinder its application as a therapeutic agent. Improving the stability and prolonging the half-life of LR18 are crucial to accelerate its application in the treatment of infectious diseases. Methods: A new cyclic peptide, C-LR18, was designed and synthesized through end-to-end cyclization of LR18 via disulfide bonds. The biological activity, half-life, and therapeutic effect of C-LR18 on Escherichia coli₋infected mice were studied. Results: C-LR18 maintained the characteristics of low cytotoxicity and low hemolytic activity of the original LR18 peptide and had higher antibacterial activity and significantly improved stability. After treatment with 1 mg/mL of trypsin, carboxypeptidase, and papain for 1 h, the MIC of C-LR18 against E. coli ATCC25922 was 4 μM, while that of LR18 had increased to 128 μM. After exposure to 50% serum or artificial gut solution for 30 min, the MIC of C-LR18 against E. coli ATCC25922 increased 4-fold, while that of LR18 increased 16-fold. The half-life of C-LR18 in plasma and in rats was extended to 3.37-fold and 4.46-fold, respectively, that of LR18. The acute toxicity of C-LR18 in mice is lower than many AMPs reported so far (LD50 = 37.8 mg/kg). C-LR18 has a therapeutic effect on E.coli-infected mice. Conclusions: The cyclic peptide C-LR18 has higher antibacterial activity and stability and a longer half-life than LR18 in rats in vitro and in vivo. C-LR18 also has a therapeutic effect on KM mice infected with E. coli and is expected to become a therapeutic drug for bacterial diseases and applied to the treatment of human and veterinary diseases. Full article

Zygophyllum coccineum L. and Haloxylon salicornicum are dominant plant species in the natural habitats of Saudi Arabia. The soil microbiome is indispensable for nutrient cycling and stress resilience. In the present study, the analysis of soil nutrients under the two plants displayed variable differences in total N, K, Zn, Mn and Cu, with significant differences in both K and Mn (p ≤ 0.05). In general, the available soil nutrients were higher under Haloxylon than Zygophyllum plants, reflecting higher N, K, Fe and Cu contents in the leaves of the Haloxylon plant. Metagenomic analysis of soil microbiome revealed that the top abundant bacteria at the phylum level were Actinobacteriota, Chloroflexi and Proteobacteria, whereas the uppermost fungal communities were Ascomycota, followed by Basidiomycota. The predicted abundant enzymes in the bacterial communities included Phosphoadenylyl-sulfate reductase, Serine-type D-Ala-carboxypeptidase, ADP-glyceromanno-heptose 6-epimerase and glutathione hydrolase. The fungal communities associated with Haloxylon possessed more than 48 enzymes that differed in their richness from the communities of Zygophyllum. Pentose-P and Sulphate-Cys pathways disclosed the extreme abundant pathways in Zygophyllum bacterial communities, while the nonoxipent pathway was overabundant in the Haloxylon fungal communities. While genomic predictions provide insights into functional potential, integrating these data with environmental parameters remains key to managing soil health. Full article

This work aimed to evaluate the effects of dried apple pomace (DAP) on the fermentation characteristics and proteolysis of alfalfa silages. The alfalfa was ensiled with (1) no additives (control), (2) 5% DAP, (3) 10% DAP and (4) 15% DAP based on fresh weight (FW) for 1, 3, 7, 14, 30 and 60 days, respectively. With the increasing proportion of DAP, lactic acid bacteria (LAB) count, lactic acid (LA) and dry matter (DM) content linearly (p < 0.05) increased, while the pH, the content of acetic acid (AA), propionic acid (PA), butyric acid (BA) and ammonia nitrogen (NH₃-N) linearly (p < 0.05) decreased during ensiling. The 10% and 15% DAP silages had significantly (p < 0.05) lower aerobic bacteria (AB), yeast and enterobacteria counts than the control during ensiling. The contents of nonprotein nitrogen (NPN), peptide nitrogen (peptide-N) and free amino acid nitrogen (FAA-N) and activities of carboxypeptidase, aminopeptidase and acid proteinase linearly (p < 0.05) decreased as DAP proportion increased during ensiling. On day 60, the addition of DAP significantly (p < 0.05) decreased the contents of tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, spermine and total biogenic amines compared with the control. As the DAP ratio increased, the contents of threonine, valine, isoleucine, leucine, phenylalanine, lysine, histidine, arginine, aspartic acid, serine, glutamic, total amino acids, crude protein (CP) and water-soluble carbohydrates (WSCs) linearly (p < 0.05) increased, while the contents of glycine, alanine, cysteine, and proline linearly (p < 0.05) decreased on day 60. Overall, the addition of 15% DAP was optimal as indicated by better fermentation quality and less proteolysis than other treatments. Full article

Metformin is the first-line medication for treating type 2 diabetes mellitus, with more than 200 million patients taking it daily. Its effects are extensive and play a positive role in multiple areas. Can its effects and potential mechanisms be explored through the urine proteome? In this study, 166 differential proteins were identified following the administration of 150 mg/(kg·d) of metformin to rats for five consecutive days. These included complement component C6, pyruvate kinase, coagulation factor X, growth differentiation factor 15, carboxypeptidase A4, chymotrypsin-like elastase family member 1, and L-lactate dehydrogenase C chain. Several of these proteins have been reported to be directly affected by metformin or associated with its effects. Multiple biological pathways enriched by these differential proteins, or proteins containing differentially modified peptides, have been reported to be associated with metformin, such as the glutathione metabolic process, negative regulation of gluconeogenesis, and the renin–angiotensin system. Additionally, some significantly changed proteins and enriched biological pathways, not yet reported to be associated with metformin’s effects, may provide clues for exploring its potential mechanisms. In conclusion, the application of the urine proteome offers a comprehensive and systematic approach to exploring the effects of drugs, providing a new perspective on the study of metformin’s mechanisms. Full article

The absence of efficient on-farm interventions against white spot syndrome viral (WSSV) infections can cause significant economic losses to shrimp farmers. With this exploratory study we aimed to test, both in vitro and in vivo, the efficacy of an organic acid mixture (Aq) against WSSV infections in shrimp. In vitro, using shrimp gut primary cells (SGP), 2% Aq significantly reduced WSSV infection and the amounts of H₂O₂ released but had no impact on CAT and SOD expression. In vivo, in a shrimp challenge test, 2% Aq significantly downregulated the expression of proteins involved in WSSV virulence, such as the lipopolysaccharide-β-1,3-glucan-binding protein (LGBP) and the TLR signalling pathway (LvECSIT), and increased the expression of HO-1 oxygenase. Additionally, at 2% Aq, the expression of the digestive-related enzyme carboxypeptidase B was upregulated in the gut, alongside a significant decrease in IL-22 expression, a cytokine usually increased during WSSV infection in shrimp. A low mortality rate (7.33%) was recorded in infected shrimp treated with 2% Aq compared to the 96.66% mortality in the absence of Aq. The peritrophic membrane (PM) was proven essential to ensure Aq efficacy, as the infected and treated PM deficient shrimp (PM−) had a mortality rate of 27.8%, compared to only 9.34% mortality in the infected shrimp at 2% Aq and in the presence of PM (PM+). Aq significantly increased the expression of mucin-1, mucin-2, mucin-5AC, mucin-5B, and mucin-19 in both PM+ and PM− shrimp. Conclusively, organic acid in mixtures can protect farmed shrimp against WSSV infection and increase their survivability through a mediated gut health effect which includes resistance to oxidative stress and improved immunity. Full article

Background/Objectives: The Pacific white shrimp (L. vannamei) is economically significant, and its growth is regulated by multiple factors. Carboxypeptidase B (CPB) is related to protein digestion, but its gene sequence and features in L. vannamei are not fully understood. This study aimed to explore the molecular and functional properties of CPB in L. vannamei. Methods: The Lv-CPB gene was cloned, and bioinformatics analysis, qRT-PCR, in situ hybridization, recombinant protein expression in Escherichia coli, and an enzyme activity assay were performed. Results: The Lv-CPB gene is 1414 bp long with a 1263 bp ORF encoding a 420-amino-acid protein. It is stable, hydrophilic, and is highly expressed in the hepatopancreas. The recombinant protein was efficiently expressed with a molecular weight of about 47 kDa. The optimal pH and temperature for Lv-CPB were 8.0 and 50 °C, respectively. Conclusions: This study revealed the molecular and functional characteristics of Lv-CPB, providing insights into its role in shrimp digestion, as well as suggestions for improving aquaculture practices. Full article

Rice plants are important food crops that are sensitive to cold stress. Microtubules (MTs) are highly associated with plant response to cold stress. The exogenous application of abscisic acid (ABA) can transiently induce the cold stability of microtubules. These phenotypes were accompanied by the transient increase in Phospholipase D (PLD) enzyme activity. The analysis of detyrosinated/tyrosinated α-tubulin by Western blot in the NtTUA3 line or in the NtTUA3+OsTTL line gave us such a conclusion that the effect of ABA on detyrosinated α-tubulin not only was regulated by ABA but also was dependent on the TTLL12 protein. The dual ABA and 1% n-butanol treatments had shown that ABA-induced detyrosinated α-tubulin in a manner distinct from the n-butanol pathway. Detecting the detyrosinated α-tubulin level after pre-treatment with pertussis toxin (PTX), a G-protein inhibitor, followed by ABA, as well as mastoparan (Mas7) treatment suggested that the effect of ABA on detyrosinated α-tubulin was dependent on PLD activity. Full article