-
Scientific Reports Jul 2023Adipokinetic hormones (AKHs) in Arthopoda are characterized by special sequence features including limited choices of amino acid residues in certain positions, such as...
Adipokinetic hormones (AKHs) in Arthopoda are characterized by special sequence features including limited choices of amino acid residues in certain positions, such as Trp in position 8. Over 100 different AKHs have been described, but de novo sequencing of novel peptide hormones can be a challenge. In a project of analyzing corpora cardiaca extracts from two fly species, two different moths, a termite and a beetle for their AKHs, we noted specific patterns in the fragmentation spectra of octapeptides in electrospray Q-TOF experiments resulting from the presence of Pro in position 6. The preference for cleavage N-terminal to Pro residues created an abundant y″-ion, which, in conjunction with the two b-ions resulting from the fragmentation before and after Pro, provided a marker pattern. As Pro6 occurs in about 61% of known AKHs, this information is highly relevant for sequence elucidation. Moreover, the default presence of Trp8 allowed the use of its immonium ion for AKH candidate identification. In addition, we assembled the known AKH sequences from the literature and sequences of AKH-type format found in the Uniprot database in a single online resource. These efforts assisted in the analysis workflow and led to the assignment of two novel AKHs and evidence for the presence of Melme-CC and Dorpa-AKH in the corpus cardiacum of the scarab beetle Sinodendron cylindricum.
Topics: Animals; Tryptophan; Amino Acid Sequence; Proline; Insect Hormones; Corpora Allata; Moths; Pyrrolidonecarboxylic Acid; Coleoptera
PubMed: 37407598
DOI: 10.1038/s41598-023-38056-2 -
Insect Molecular Biology Dec 2023Adipokinetic hormone (AKH) is a neuropeptide produced in the insect corpora cardiaca that plays an essential role in mobilising carbohydrates and lipids from the fat...
Adipokinetic hormone (AKH) is a neuropeptide produced in the insect corpora cardiaca that plays an essential role in mobilising carbohydrates and lipids from the fat body to the haemolymph. AKH acts by binding to a rhodopsin-like G protein-coupled receptor (GPCR), the adipokinetic hormone receptor (AKHR). In this study, we tackle AKH ligand and receptor gene evolution as well as the evolutionary origins of AKH gene paralogues from the order Blattodea (termites and cockroaches). Phylogenetic analyses of AKH precursor sequences point to an ancient AKH gene duplication event in the common ancestor of Blaberoidea, yielding a new group of putative decapeptides. In total, 16 different AKH peptides from 90 species were obtained. Two octapeptides and seven putatively novel decapeptides are predicted for the first time. AKH receptor sequences from 18 species, spanning solitary cockroaches and subsocial wood roaches as well as lower and higher termites, were subsequently acquired using classical molecular methods and in silico approaches employing transcriptomic data. Aligned AKHR open reading frames revealed 7 highly conserved transmembrane regions, a typical arrangement for GPCRs. Phylogenetic analyses based on AKHR sequences support accepted relationships among termite, subsocial (Cryptocercus spp.) and solitary cockroach lineages to a large extent, while putative post-translational modification sites do not greatly differ between solitary and subsocial roaches and social termites. Our study provides important information not only for AKH and AKHR functional research but also for further analyses interested in their development as potential candidates for biorational pest control agents against invasive termites and cockroaches.
Topics: Animals; Cockroaches; Phylogeny; Oligopeptides; Insect Hormones; Pyrrolidonecarboxylic Acid
PubMed: 37382487
DOI: 10.1111/imb.12861 -
International Journal of Molecular... Jun 2023Post-translationally modified N-terminally truncated amyloid beta peptide with a cyclized form of glutamate at position 3 (pEAβ) is a highly pathogenic molecule with...
Post-translationally modified N-terminally truncated amyloid beta peptide with a cyclized form of glutamate at position 3 (pEAβ) is a highly pathogenic molecule with increased neurotoxicity and propensity for aggregation. In the brains of Alzheimer's Disease (AD) cases, pEAβ represents a major constituent of the amyloid plaque. The data show that pEAβ formation is increased at early pre-symptomatic disease stages, while tau phosphorylation and aggregation mostly occur at later stages of the disease. This suggests that pEAβ accumulation may be an early event in the disease pathogenesis and can be prophylactically targeted to prevent the onset of AD. The vaccine (AV-1986R/A) was generated by chemically conjugating the pEAβ fragment to our universal immunogenic vaccine platform MultiTEP, then formulated in Advax adjuvant. AV-1986R/A showed high immunogenicity and selectivity, with endpoint titers in the range of 10-10 against pEAβ and 10-10 against the full-sized peptide in the 5XFAD AD mouse model. The vaccination showed efficient clearance of the pathology, including non-pyroglutamate-modified plaques, from the mice brains. AV-1986R/A is a novel promising candidate for the immunoprevention of AD. It is the first late preclinical candidate which selectively targets a pathology-specific form of amyloid with minimal immunoreactivity against the full-size peptide. Successful translation into clinic may offer a new avenue for the prevention of AD via vaccination of cognitively unimpaired individuals at risk of disease.
Topics: Mice; Animals; Alzheimer Disease; Amyloid beta-Peptides; Pyrrolidonecarboxylic Acid; Cancer Vaccines; Immunotherapy; Plaque, Amyloid; Brain; Mice, Transgenic; Disease Models, Animal
PubMed: 37372944
DOI: 10.3390/ijms24129797 -
Physical Chemistry Chemical Physics :... Jun 2023The aggregation of the amyloid β (Aβ) peptide is a major hallmark of Alzheimer's disease. This peptide can aggregate into oligomers, proto-fibrils and mature fibrils,...
The aggregation of the amyloid β (Aβ) peptide is a major hallmark of Alzheimer's disease. This peptide can aggregate into oligomers, proto-fibrils and mature fibrils, which eventually assemble into amyloid plaques . Several post-translational modifications lead to the presence of different forms of the Aβ peptide in the amyloid plaques with different biophysical and biochemical properties. While the canonical forms Aβ(1-40) and Aβ(1-42) have been found to be the major components of amyloid plaques, N-terminally pyroglutamate-modified variants, specifically pE-Aβ(3-42), amount to a significant fraction of the total Aβ plaque content of AD brains. With increased hydrophobicity, these variants display a more pronounced aggregation behaviour which, together with their higher stability against degradation is thought to make them crucial molecular players in the aetiology of AD. The peptide monomers are the smallest assembly units, and play an important role in most of the individual molecular processes involved in amyloid fibril formation, such as primary and secondary nucleation and elongation. Understanding the monomeric conformational ensembles of the isoforms is important in unraveling observed differences in their bio-physico-chemical properties. Here we use enhanced and extensive molecular dynamics simulations to study the structural flexibility of the N-terminally truncated Pyroglutamate modified isomer of Aβ, pE-Aβ(3-42) monomer, and compared it with simulations of the Aβ(1-42) peptide monomer under the same conditions. We find significant differences, especially in the secondary structure and hydrophobic exposure, which might be responsible for their different behaviour in biophysical experiments.
Topics: Humans; Amyloid beta-Peptides; Pyrrolidonecarboxylic Acid; Protein Conformation, beta-Strand; Plaque, Amyloid; Alzheimer Disease; Amyloid; Peptide Fragments
PubMed: 37306611
DOI: 10.1039/d2cp05961d -
Archives of Insect Biochemistry and... Sep 2023Glutathione (GSH) contributes to redox maintenance and detoxification of various xenobiotic and endogenous substances. γ-glutamyl cyclotransferase (ChaC) is involved in... (Review)
Review
Glutathione (GSH) contributes to redox maintenance and detoxification of various xenobiotic and endogenous substances. γ-glutamyl cyclotransferase (ChaC) is involved in GSH degradation. However, the molecular mechanism underlying GSH degradation in silkworms (Bombyx mori) remains unknown. Silkworms are lepidopteran insects that are considered to be an agricultural pest model. We aimed to examine the metabolic mechanism underlying GSH degradation mediated by B. mori ChaC and successfully identified a novel ChaC gene in silkworms (herein, bmChaC). The amino acid sequence and phylogenetic tree revealed that bmChaC was closely related to mammalian ChaC2. We overexpressed recombinant bmChaC in Escherichia coli, and the purified bmChaC showed specific activity toward GSH. Additionally, we examined the degradation of GSH to 5-oxoproline and cysteinyl glycine via liquid chromatography-tandem mass spectrometry. Quantitative real-time polymerase chain reaction revealed that bmChaC mRNA expression was observed in various tissues. Our results suggest that bmChaC participates in tissue protection via GSH homeostasis. This study provides new insights into the activities of ChaC and the underlying molecular mechanisms that can aid the development of insecticides to control agricultural pests.
Topics: Animals; Bombyx; Phylogeny; Pyrrolidonecarboxylic Acid; Amino Acid Sequence; Glutathione; Mammals
PubMed: 37283485
DOI: 10.1002/arch.22027 -
Comparative Biochemistry and... Aug 2023In this study, the biochemical and physiological features of the firebug Pyrrhocoris apterus were investigated to understand the impact of the honeybee Apis mellifera...
In this study, the biochemical and physiological features of the firebug Pyrrhocoris apterus were investigated to understand the impact of the honeybee Apis mellifera venom on them using physiological methods (mortality, total level of metabolism), biochemical methods (ELISA, mass spectrometry, polyacrylamide gel electrophoresis, spectrophotometry) and molecular methods (real-time PCR). Together, the obtained findings suggest that venom injection increased the level of adipokinetic hormone (AKH) in the CNS of P. apterus, indicating that this hormone plays a key role in activating defence responses. Furthermore, histamine levels in the gut increased significantly after envenomation and did not seem to be modulated by AKH. In contrast, histamine levels in the haemolymph increased after treatment with AKH and AKH + venom. In addition, we found that vitellogenin levels in haemolymph decreased in both males and females after venom application. Lipids, which are the main energy metabolites used by Pyrrhocoris, were significantly exhausted from the haemolymph after the administration of venom and the co-application with AKH reversed this effect. However, we did not find much influence on the effect of digestive enzymes after the injection of venom. Our research has highlighted the noticeable effect of bee venom on P. apterus' body and provided new insights into the role of AKH in controlling defensive responses. However, it is also likely that there will be alternative defence mechanisms.
Topics: Female; Male; Animals; Bee Venoms; Histamine; Heteroptera; Insect Hormones; Pyrrolidonecarboxylic Acid
PubMed: 37196854
DOI: 10.1016/j.cbpc.2023.109657 -
Archives of Insect Biochemistry and... Jul 2023Previous studies had shown that the corpora cardiaca (CC) of the Indian stick insect, Carausius morosus, synthesizes two hypertrehalosemic hormones (HrTHs)-decapeptides...
Previous studies had shown that the corpora cardiaca (CC) of the Indian stick insect, Carausius morosus, synthesizes two hypertrehalosemic hormones (HrTHs)-decapeptides which differ in the way that the chromatographically less-hydrophobic form, code-named Carmo-HrTH-I, is modified by an unique C-mannosylated tryptophan residue at position 8. The availability of milligram amounts of this modified peptide in synthetic form now makes it possible to study physico-chemical and physiological properties. This study revealed that the synthetic peptide co-elutes with the natural peptide from the CC chromatographically, is heat stable for at least 30 min at 100°C, and causes hyperlipemia in acceptor locusts (a heterologous bioassay) and hypertrehalosemia in ligated stick insects (conspecific bioassay). In vitro incubation of Carmo-HrTH-I together with stick insect hemolymph (a natural source of peptidases) demonstrated clearly via chromatographic separation that the C-mannosylated Trp bond is stable and is not broken down to Carmo-HrTH-II (the more-hydrophobic decapeptide with an unmodified Trp residue). This notwithstanding, breakdown of Carmo-HrTH-I did take place, and the half-life of the compound was calculated as about 5 min. Finally, the natural peptide is releasable when CC are treated in vitro with a depolarizing saline (high potassium concentration) suggesting its role as true HrTHs in the stick insect. In conclusion, the results indicate that Carmo-HrTH-I which is synthesized in the CC is released into the hemolymph, binds to a HrTH receptor in the fat body, activates the carbohydrate metabolism pathway and is quickly inactivated in the hemolymph by (an) as yet unknown peptidase(s).
Topics: Animals; Amino Acid Sequence; Oligopeptides; Neuropeptides; Insecta; Peptides; Neoptera; Insect Hormones; Pyrrolidonecarboxylic Acid
PubMed: 37073494
DOI: 10.1002/arch.22016 -
The American Journal of Case Reports Apr 2023BACKGROUND Glutathione synthetase deficiency (GSD) is a rare autosomal recessive disorder caused by glutathione synthetase (GSS) gene variants that occur in 1 in 1...
BACKGROUND Glutathione synthetase deficiency (GSD) is a rare autosomal recessive disorder caused by glutathione synthetase (GSS) gene variants that occur in 1 in 1 million individuals. The severe form of GSD is characterized by hemolytic anemia, metabolic acidosis with 5-oxoprolinuria, progressive neurological symptoms, and recurrent bacterial infections. This case report presents a male Japanese infant with severe hemolytic anemia and metabolic acidosis at birth caused by GSD, who developed progressive neurological symptoms on follow-up. CASE REPORT A Japanese male term infant developed severe hemolytic anemia and metabolic acidosis in the early neonatal period. We suspected GSD based on his symptoms and a high 5-oxoproline urine concentration. We began correcting his metabolic acidosis and administering vitamins C and E supplements. The patient required blood transfusion twice during the acute phase for hemolytic anemia. After age 1 month, he maintained good control of metabolic acidosis and hemolytic anemia. A definitive diagnosis of GSD was made based on high concentrations of 5-oxoproline in urine, low concentrations of glutathione and GSS activity in erythrocytes, and genetic testing. Several episodes of febrile convulsions were started at age 11 months, but none occurred after 2 years. At the last follow-up at age 25 months, metabolic acidosis and hemolytic anemia were well controlled, but he had mild neurodevelopmental delay. CONCLUSIONS This case report shows that GSD can present with severe hemolytic anemia and metabolic acidosis at birth, and manifest with subsequent neurological impairment despite early diagnosis and treatment. Therefore, a careful long-term follow-up that includes neurological evaluation is essential for patients with GSD.
Topics: Infant, Newborn; Infant; Humans; Male; Child, Preschool; Glutathione Synthase; Pyrrolidonecarboxylic Acid; Follow-Up Studies; Anemia, Hemolytic; Acidosis
PubMed: 37050856
DOI: 10.12659/AJCR.938396 -
Metabolomics : Official Journal of the... Mar 2023Increased exposure to risk factors in the young and healthy contributes to arterial changes, which may be accompanied by an altered metabolism.
INTRODUCTION
Increased exposure to risk factors in the young and healthy contributes to arterial changes, which may be accompanied by an altered metabolism.
OBJECTIVES
To increase our understanding of early metabolic alterations and how they associate with markers of arterial stiffness, we profiled urinary metabolites in young adults with cardiovascular disease (CVD) risk factor(s) and in a control group without CVD risk factors.
METHODS
We included healthy black and white women and men (N = 1202), aged 20-30 years with a detailed CVD risk factor profile, reflecting obesity, physical inactivity, smoking, excessive alcohol intake, masked hypertension, hyperglycemia, dyslipidemia and low socio-economic status, forming the CVD risk group (N = 1036) and the control group (N = 166). Markers of arterial stiffness, central systolic blood pressure (BP) and pulse wave velocity were measured. A targeted metabolomics approach was followed by measuring amino acids and acylcarnitines using a liquid chromatography-tandem mass spectrometry method.
RESULTS
In the CVD risk group, central systolic BP (adjusted for age, sex, ethnicity) was negatively associated with histidine, arginine, asparagine, serine, glutamine, dimethylglycine, threonine, GABA, proline, methionine, pyroglutamic acid, aspartic acid, glutamic acid, branched chain amino acids (BCAAs) and butyrylcarnitine (all P ≤ 0.048). In the same group, pulse wave velocity (adjusted for age, sex, ethnicity, mean arterial pressure) was negatively associated with histidine, lysine, threonine, 2-aminoadipic acid, BCAAs and aromatic amino acids (AAAs) (all P ≤ 0.044). In the control group, central systolic BP was negatively associated with pyroglutamic acid, glutamic acid and dodecanoylcarnitine (all P ≤ 0.033).
CONCLUSION
In a group with increased CVD risk, markers of arterial stiffness were negatively associated with metabolites related to AAA and BCAA as well as energy metabolism and oxidative stress. Our findings may suggest that metabolic adaptations may be at play in response to increased CVD risk to maintain cardiovascular integrity.
Topics: Male; Humans; Female; Young Adult; Cardiovascular Diseases; Risk Factors; Metabolomics; Vascular Stiffness; Histidine; Pyrrolidonecarboxylic Acid; Pulse Wave Analysis; Amino Acids, Branched-Chain; Heart Disease Risk Factors; Threonine
PubMed: 36988718
DOI: 10.1007/s11306-023-01987-y -
Journal of Alzheimer's Disease : JAD 2023The lysosomal cysteine protease cathepsin B (CTSB) has been suggested as a biomarker for Alzheimer's disease (AD) because elevated serum CTSB in AD patients has been... (Review)
Review
The lysosomal cysteine protease cathepsin B (CTSB) has been suggested as a biomarker for Alzheimer's disease (AD) because elevated serum CTSB in AD patients has been found to correlate with cognitive dysfunction. Furthermore, CTSB gene knockout (KO) in non-transgenic and transgenic AD animal models showed that elimination of CTSB improved memory deficits. However, conflicting CTSB KO results on amyloid-β (Aβ) pathology in transgenic AD models have been reported. The conflict is resolved here as likely being due to the different hAβPP transgenes used in the different AD mouse models. CTSB gene KO reduced wild-type (Wt) β-secretase activity, brain Aβ, pyroglutamate-Aβ, amyloid plaque, and memory deficits in models that used cDNA transgenes expressing hAβPP isoform 695. But in models that used mutated mini transgenes expressing hAβPP isoforms 751 and 770, CTSB KO had no effect on Wt β-secretase activity and slightly increased brain Aβ. All models expressed the AβPP transgenes in neurons. These conflicting results in Wt β-secretase activity models can be explained by hAβPP isoform specific cellular expression, proteolysis, and subcellular processing. CTSB KO had no effect on Swedish mutant (Swe) β-secretase activity in hAβPP695 and hAβPP751/770 models. Different proteolytic sensitivities for hAβPP with Wt versus Swe β-secretase site sequences may explain the different CTSB β-secretase effects in hAβPP695 models. But since the vast majority of sporadic AD patients have Wt β-secretase activity, the CTSB effects on Swe β-secretase activity are of little importance to the general AD population. As neurons naturally produce and process hAβPP isoform 695 and not the 751 and 770 isoforms, only the hAβPP695 Wt models mimic the natural neuronal hAβPP processing and Aβ production occurring in most AD patients. Significantly, these CTSB KO findings in the hAβPP695 Wt models demonstrate that CTSB participates in memory deficits and production of pyroglutamate-Aβ (pyroglu-Aβ), which provide rationale for future investigation of CTSB inhibitors in AD therapeutics development.
Topics: Mice; Animals; Alzheimer Disease; Cathepsin B; Amyloid Precursor Protein Secretases; Pyrrolidonecarboxylic Acid; Amyloid beta-Peptides; Memory Disorders; Disease Models, Animal; Amyloid beta-Protein Precursor; Mice, Transgenic
PubMed: 36970896
DOI: 10.3233/JAD-221005