-
Toxins Dec 2021Bees originally developed their stinging apparatus and venom against members of their own species from other hives or against predatory insects. Nevertheless, the...
Bees originally developed their stinging apparatus and venom against members of their own species from other hives or against predatory insects. Nevertheless, the biological and biochemical response of arthropods to bee venom is not well studied. Thus, in this study, the physiological responses of a model insect species (American cockroach, ) to honeybee venom were investigated. Bee venom toxins elicited severe stress (LD = 1.063 uL venom) resulting in a significant increase in adipokinetic hormones (AKHs) in the cockroach central nervous system and haemolymph. Venom treatment induced a large destruction of muscle cell ultrastructure, especially myofibrils and sarcomeres. Interestingly, co-application of venom with cockroach Peram-CAH-II AKH eliminated this effect. Envenomation modulated the levels of carbohydrates, lipids, and proteins in the haemolymph and the activity of digestive amylases, lipases, and proteases in the midgut. Bee venom significantly reduced vitellogenin levels in females. Dopamine and glutathione (GSH and GSSG) insignificantly increased after venom treatment. However, dopamine levels significantly increased after Peram-CAH-II application and after co-application with bee venom, while GSH and GSSG levels immediately increased after co-application. The results suggest a general reaction of the cockroach body to bee venom and at least a partial involvement of AKHs.
Topics: Animals; Bee Venoms; Central Nervous System; Hemolymph; Immunity, Innate; Insect Hormones; Oligopeptides; Periplaneta; Pyrrolidonecarboxylic Acid
PubMed: 35050987
DOI: 10.3390/toxins14010011 -
Journal of Microbiology and... Feb 2023Taste is classified into five types, each of which has evolved to play its respective role in mammalian survival. Sour taste is one of the important ways to judge...
Taste is classified into five types, each of which has evolved to play its respective role in mammalian survival. Sour taste is one of the important ways to judge whether food has gone bad, and the sour taste receptor (PKD2L1) is the gene behind it. Here, we investigated whether L-pyroglutamic acid interacts with sour taste receptors through electrophysiology and mutation experiments using oocytes. R299 of hPKD2L1 was revealed to be involved in L-pyroglutamic acid binding in a concentration-dependent manner. As a result, it is possible to objectify the change in signal intensity according to the concentration of L-pyroglutamic acid, an active ingredient involved in the taste of kimchi, at the molecular level. Since the taste of other ingredients can also be measured with the method used in this experiment, it is expected that an objective database of taste can be created.
Topics: Animals; Humans; Calcium Channels; Pyrrolidonecarboxylic Acid; Receptors, Cell Surface; Taste; Taste Buds; Xenopus laevis
PubMed: 36655284
DOI: 10.4014/jmb.2212.12007 -
The formation of pyrrolid-2-one-5-carboxylic acid at the N-terminus of immunoglobulin G heavy chain.The Biochemical Journal Aug 1972We propose that pyrrolid-2-one-5-carboxyl-tRNA is not involved in the initiation of protein synthesis in eukaryotic cells and that the N-terminal...
We propose that pyrrolid-2-one-5-carboxyl-tRNA is not involved in the initiation of protein synthesis in eukaryotic cells and that the N-terminal pyrrolid-2-one-5-carboxylic acid group of an IgG (immunoglobulin G) (that secreted by the mouse plasmacytoma Adj PC5) is formed by the enzymic cyclization of the N-terminal glutamine of the heavy chain of the completed IgG molecule and that the cyclization takes place inside the cell. We base these conclusions on the following evidence. (1) Pyrrolidonecarboxyl-tRNA was not found in incorporation experiments with rat liver preparations and [U-(14)C]-pyrrolidonecarboxylic acid, glutamic acid and glutamine, even though an incorporation extent of less than 2% of the total products could have been detected. (2) Double-labelling experiments showed that less than 8% of the nascent peptides of heavy chains (those obtained by precipitation by the antibody to Fc fragment) began with pyrrolidonecarboxylic acid. (3) Further double-labelling experiments showed that 60-66% of the heavy chains of the completed intracellular IgG molecule began with pyrrolidonecarboxylic acid after both 1 and 5h of labelling. (4) The IgG, after secretion by plasmacytoma Adj PC5, was found to have the sequence [unk]Glu- Val-Gln-Leu- at the N-termini of the heavy chains.
Topics: Amino Acid Sequence; Amino Acids; Animals; Carbon Isotopes; Glutamine; Immunoglobulin Fc Fragments; Immunoglobulin Fragments; Immunoglobulin G; Liver; Mice; Plasmacytoma; Pyrrolidinones; Pyrrolidonecarboxylic Acid; RNA, Transfer; Tritium; Valine
PubMed: 4674626
DOI: 10.1042/bj1281221 -
Frontiers in Endocrinology 2021Red pigment concentrating hormone (RPCH) and pigment dispersing hormone (PDH) are crustacean neuropeptides involved in broad physiological processes including body color...
Red pigment concentrating hormone (RPCH) and pigment dispersing hormone (PDH) are crustacean neuropeptides involved in broad physiological processes including body color changes, circadian rhythm, and ovarian growth. In this study, the full-length cDNA of and were identified from the brain of the Chinese mitten crab . The deduced RPCH and PDH mature peptides shared identical sequence to the adipokinetic hormone/RPCH peptides family and the β-PDH isoforms and were designated as Es-RPCH and Es-β-PDH, respectively. and transcripts were distributed in the brain and eyestalks. The positive signals of and were localized in the neuronal clusters 6, 8, 9, 10, and 17 of the brain as revealed by hybridization. The expression level of and mRNA in nervous tissues were all significantly increased at vitellogenic stage, and then decreased at the final meiotic maturation stage. The administrated with synthesized Es-RPCH peptide results in germinal vesicles shift toward the plasma membrane in vitellogenic oocyte, and significant decrease of the gonad-somatic index (GSI) and mean oocyte diameter as well as the expression of vitellogenin mRNA at 30 days post injection . Similar results were also found when injection of the Es-β-PDH peptide. culture demonstrated that Es-RPCH and Es-β-PDH induced germinal vesicle breakdown of the late vitellogenic oocytes. Comparative ovarian transcriptome analysis indicated that some reproduction/meiosis-related genes such as cdc2 kinase, cyclin B, 5-HT-R and retinoid-X receptor were significantly upregulated in response to Es-RPCH and Es-β-PDH treatments. Taken together, these results provided the evidence for the inductive effect of and on the oocyte meiotic maturation in .
Topics: Animals; Brachyura; Brain Chemistry; China; DNA, Complementary; Female; Gene Expression; Meiosis; Oligopeptides; Oocytes; Ovary; Peptides; Pyrrolidonecarboxylic Acid; RNA, Messenger; Vitellogenesis
PubMed: 34975771
DOI: 10.3389/fendo.2021.802768 -
Arthritis Research & Therapy Dec 2021Humidity was an unfavorable factor for patients with rheumatoid arthritis (RA). RA disease activity was severe in high humidity conditions. However, there is no evidence...
BACKGROUND
Humidity was an unfavorable factor for patients with rheumatoid arthritis (RA). RA disease activity was severe in high humidity conditions. However, there is no evidence to demonstrate the effects of humidity on arthritis in the animal experiments and explore its relevant mechanism.
METHODS
Using the DBA/1 mice, this study addressed the effects of a high humidity (80 ± 5%) on arthritis in collagen-induced arthritis (CIA) mice. Then, this study used the gas chromatography-mass spectrometer (GC-MS) to explore alterations in serum metabolome caused by the high humidity. Furthermore, xylitol and L-pyroglutamic acid, which were both significantly upregulated by the high humidity, were selected to further study their effects on arthritis in the CIA mice.
RESULTS
The high humidity (80 ± 5%) could aggravate arthritis variables including increasing arthritis score and swelling, serum autoantibodies (anti-COII and anti-CCP), and proinflammatory cytokines (IL-6, IL-17A, and G-CSF). In addition, the high humidity could cause significant alterations in serum metabolome in the CIA mice. Xylitol and L-pyroglutamic acid were the representative serum metabolites that were significantly upregulated by the high humidity. Further experiments demonstrated that the supplementation of 0.4 mg/mL xylitol in drinking water after inducing the CIA model and 2.0 mg/mL in drinking water before inducing the CIA model could both aggravate arthritis in the CIA mice.
CONCLUSIONS
These data demonstrated that high humidity was not beneficial for arthritis development and its mechanism might be associated with xylitol and L-pyroglutamic acid.
Topics: Animals; Arthritis, Experimental; Cytokines; Humidity; Mice; Mice, Inbred DBA; Pyrrolidonecarboxylic Acid; Xylitol
PubMed: 34852827
DOI: 10.1186/s13075-021-02681-x -
Massive glutamine cyclization to pyroglutamic acid in human serum discovered using NMR spectroscopy.Analytical Chemistry Apr 2015Glutamine is one of the most abundant metabolites in blood and is a precursor as well as end product central to numerous important metabolic pathways. A number of...
Glutamine is one of the most abundant metabolites in blood and is a precursor as well as end product central to numerous important metabolic pathways. A number of surprising and unexpected roles for glutamine, including cancer cell glutamine addiction discovered recently, stress the importance of accurate analysis of glutamine concentrations for understanding its role in health and numerous diseases. Utilizing a recently developed NMR approach that offers access to an unprecedented number of quantifiable blood metabolites, we have identified a surprising glutamine cyclization to pyroglutamic acid that occurs during protein removal. Intact, ultrafiltered and protein precipitated samples from the same pool of human serum were comprehensively investigated using (1)H NMR spectroscopy at 800 MHz to detect and quantitatively evaluate the phenomenon. Interestingly, although glutamine cyclization occurs in both ultrafiltered and protein precipitated serum, the cyclization was not detected in intact serum. Strikingly, due to cyclization, the apparent serum glutamine level drops by up to 75% and, concomitantly, the pyroglutamic acid level increases proportionately. Further, virtually under identical conditions, the magnitude of cyclization is vastly different for different portions of samples from the same pool of human serum. However, the sum of glutamine and pyroglutamic acid concentrations in each sample remains the same for all portions. These unexpected findings indicate the importance of considering the sum of apparent glutamine and pyroglutamic acid levels, obtained from the contemporary analytical methods, as the actual blood glutamine level for biomarker discovery and biological interpretations.
Topics: Cyclization; Glutamine; Humans; Magnetic Resonance Spectroscopy; Pyrrolidonecarboxylic Acid
PubMed: 25746059
DOI: 10.1021/ac504435b -
Current Biology : CB Sep 2021Animals need to balance competitive behaviors to maintain internal homeostasis. The underlying mechanisms are complex but typically involve neuroendocrine signaling....
Animals need to balance competitive behaviors to maintain internal homeostasis. The underlying mechanisms are complex but typically involve neuroendocrine signaling. Using Drosophila, we systematically manipulated signaling between energy-mobilizing endocrine cells producing adipokinetic hormone (AKH), octopaminergic neurons, and the energy-storing fat body to assess whether this neuroendocrine axis involved in starvation-induced hyperactivity also balances activity levels under ad libitum access to food. Our results suggest that AKH signals via two divergent pathways that are mutually competitive in terms of activity and rest. AKH increases activity via the octopaminergic system during the day, while it prevents high activity levels during the night by signaling to the fat body. This regulation involves feedback signaling from octopaminergic neurons to AKH-producing cells (APCs). APCs are known to integrate a multitude of metabolic and endocrine signals. Our results add a new facet to the versatile regulatory functions of APCs by showing that their output contributes to shape the daily activity pattern under ad libitum access to food.
Topics: Animals; Drosophila; Homeostasis; Insect Hormones; Neurons; Pyrrolidonecarboxylic Acid; Signal Transduction; Starvation
PubMed: 34329588
DOI: 10.1016/j.cub.2021.07.002 -
EBioMedicine Sep 2021Respiratory virus infections are significant causes of morbidity and mortality, and may induce host metabolite alterations by infecting respiratory epithelial cells. We...
BACKGROUND
Respiratory virus infections are significant causes of morbidity and mortality, and may induce host metabolite alterations by infecting respiratory epithelial cells. We investigated the use of liquid chromatography quadrupole time-of-flight mass spectrometry (LC/Q-TOF) combined with machine learning for the diagnosis of influenza infection.
METHODS
We analyzed nasopharyngeal swab samples by LC/Q-TOF to identify distinct metabolic signatures for diagnosis of acute illness. Machine learning models were performed for classification, followed by Shapley additive explanation (SHAP) analysis to analyze feature importance and for biomarker discovery.
FINDINGS
A total of 236 samples were tested in the discovery phase by LC/Q-TOF, including 118 positive samples (40 influenza A 2009 H1N1, 39 influenza H3 and 39 influenza B) as well as 118 age and sex-matched negative controls with acute respiratory illness. Analysis showed an area under the receiver operating characteristic curve (AUC) of 1.00 (95% confidence interval [95% CI] 0.99, 1.00), sensitivity of 1.00 (95% CI 0.86, 1.00) and specificity of 0.96 (95% CI 0.81, 0.99). The metabolite most strongly associated with differential classification was pyroglutamic acid. Independent validation of a biomarker signature based on the top 20 differentiating ion features was performed in a prospective cohort of 96 symptomatic individuals including 48 positive samples (24 influenza A 2009 H1N1, 5 influenza H3 and 19 influenza B) and 48 negative samples. Testing performed using a clinically-applicable targeted approach, liquid chromatography triple quadrupole mass spectrometry, showed an AUC of 1.00 (95% CI 0.998, 1.00), sensitivity of 0.94 (95% CI 0.83, 0.98), and specificity of 1.00 (95% CI 0.93, 1.00). Limitations include lack of sample suitability assessment, and need to validate these findings in additional patient populations.
INTERPRETATION
This metabolomic approach has potential for diagnostic applications in infectious diseases testing, including other respiratory viruses, and may eventually be adapted for point-of-care testing.
FUNDING
None.
Topics: Adolescent; Adult; Child; Child, Preschool; Female; Gas Chromatography-Mass Spectrometry; Humans; Influenza, Human; Machine Learning; Male; Metabolome; Metabolomics; Molecular Diagnostic Techniques; Nasal Mucosa; Orthomyxoviridae; Pyrrolidonecarboxylic Acid
PubMed: 34419924
DOI: 10.1016/j.ebiom.2021.103546 -
Cells Dec 2020Insect adipokinetic hormones (AKHs) are short peptides produced in the corpora cardiaca and are responsible for mobilizing energy stores from the fat body to the...
Insect adipokinetic hormones (AKHs) are short peptides produced in the corpora cardiaca and are responsible for mobilizing energy stores from the fat body to the hemolymph. Three related peptides, AKH1, AKH2, and AKH/corazonin-related peptide (ACP) as well as three AKH receptors have been reported in . AKH1 and AKH2 are specific for the AKHR1 receptor, whereas ACP interacts with the other two AKHRs. To assess the effect of the two silkworm AKHs and ACP in the regulation of energy homeostasis we examined the expression pattern of the three peptides and their receptors as well as their effect on the level of carbohydrates and lipids in the hemolymph. Our results support the hypothesis that only AKH1 and AKH2 peptides together with the AKHR1 receptor are involved in the maintenance of energy homeostasis. Because AKHR1 (BmAKHR1) seems to be a true AKHR we generated its mutation. The mutant larvae display significantly lower carbohydrate and lipid levels in the hemolymph and reduced sensitivity to starvation. Our study clarifies the role of BmAKHR1 in energy homeostasis.
Topics: Animals; Bombyx; Carbohydrates; Energy Metabolism; Gene Expression Regulation; Hemolymph; Insect Hormones; Insect Proteins; Larva; Lipids; Mutagenesis; Neuropeptides; Oligopeptides; Protein Isoforms; Pyrrolidonecarboxylic Acid; Receptors, Glucagon; Signal Transduction
PubMed: 33322530
DOI: 10.3390/cells9122667 -
Biomolecules Aug 2019In the current study, pyroglutamic acid (pGlu), a natural amino acid derivative, has efficiently inhibited the catalytic activities of three important enzymes, namely:...
A Multi-Biochemical and In Silico Study on Anti-Enzymatic Actions of Pyroglutamic Acid against PDE-5, ACE, and Urease Using Various Analytical Techniques: Unexplored Pharmacological Properties and Cytotoxicity Evaluation.
In the current study, pyroglutamic acid (pGlu), a natural amino acid derivative, has efficiently inhibited the catalytic activities of three important enzymes, namely: Human recombinant phosphodiesterase-5A1 (PDE5A1), human angiotensin-converting enzyme (ACE), and urease. These enzymes were reported to be associated with several important clinical conditions in humans. Radioactivity-based assay, spectrophotometric-based assay, and an Electrospray Ionization-Mass Spectrometry-based method were employed to ascertain the inhibitory actions of pGlu against PDE5A1, ACE, and urease, respectively. The results unveiled that pGlu potently suppressed the activity of PDE5A1 (half-maximal inhibitory concentration; IC = 5.23 µM) compared with that of standard drug sildenafil citrate (IC = 7.14 µM). Moreover, pGlu at a concentration of 20 µg/mL was found to efficiently inhibit human ACE with 98.2% inhibition compared with that of standard captopril (99.6%; 20 µg/mL). The urease-catalyzed reaction was also remarkably inactivated by pGlu and standard acetohydroxamic acid with IC values of 1.8 and 3.9 µM, respectively. Remarkably, the outcome of in vitro cytotoxicity assay did not reveal any significant cytotoxic properties of pGlu against human cervical carcinoma cells and normal human fetal lung fibroblast cells. In addition to in vitro assays, molecular docking analyses were performed to corroborate the outcomes of in vitro results with predicted structure-activity relationships. In conclusion, pGlu could be presented as a natural and multifunctional agent with promising applications in the treatment of some ailments connected with the above-mentioned anti-enzymatic properties.
Topics: Binding Sites; Captopril; Cell Line; Cell Survival; Cyclic Nucleotide Phosphodiesterases, Type 5; Humans; Hydroxamic Acids; Inhibitory Concentration 50; Molecular Docking Simulation; Peptidyl-Dipeptidase A; Protein Structure, Tertiary; Pyrrolidonecarboxylic Acid; Recombinant Proteins; Sildenafil Citrate; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry; Structure-Activity Relationship; Urease
PubMed: 31438631
DOI: 10.3390/biom9090392