Octapeptide

α-Amanitin (AMN) is one of the deadliest toxins from mushrooms, present in the deadly mushroom species Amanita phalloides . It is a bicyclic octapeptide and represents up to 40% of the amatoxins in mushrooms, damaging the liver and kidneys. Current methods of detecting amatoxins are time-consuming and require the use of expensive equipment. A novel label-free electrochemical immunosensor was successfully developed for rapid detection of α-amanitin, which was fabricated by immobilization of anti-α-amanitin antibodies onto a functionalized cellulose nanofibrous membrane-modified carbon screen-printed electrode...

BACKGROUND: Hair loss occurs due to various biological and environmental causes, which can have psychosocial consequences. The Wnt/β-catenin signaling is well-known for its role in hair growth and regeneration, as it induces the proliferation and differentiation of hair cells. When the leucine-rich G protein-coupled receptor 5 (Lgr5) interacts with the R-spondins, the frizzled receptor (FZD), a Wnt receptor, becomes stabilized, resulting in an increased β-catenin activity...

OBJECTIVE: This study aimed to explore the mechanism of Fuzi Lizhong Tang (FZLZT) in treating gastric cancer using network pharmacology and molecular docking, and to validate the results through in vitro experiments. MATERIALS AND METHODS: Active ingredients and target genes of FZLZT were obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, while disease targets of gastric cancer were collected from GeneCards, OMIM, and DrugBank databases...

Solid-phase peptide synthesis (SPPS) is an essential technique for the synthesis of peptide. For half a century, many amine detection methods have been developed to monitor coupling reactions during SPPS. Despite such efforts, to the best of our knowledge, a nondestructive and quantitative colorimetric method has not been developed. Here, we developed the first quantitative and nondestructive colorimetric amine detection method based on an acid-base reaction between HCl salt of electron donor-acceptor type dyes and amino groups on the resin...

Objective: To explore the mechanism of early pancreatic exocrine function changes in severely scalded rats. Methods: The experimental research methods was used. Eighty male Sprague-Dawley rats aged 7-8 weeks were divided into simple sham injury group ( n =8), sham injury+cholecystokinin octapeptide (CCK8) group ( n =8), severe scald+CCK8 group ( n =32), and extremely severe scald+CCK8 group ( n =32) by the random number table, which were treated accordingly. Immediately after injury of rats in the 2 sham injury groups and 1, 2, 3, and 7 days after injury of rats in the 2 scald groups, the improved methods including pancreatic duct puncture and catheterization were used to dynamically collect the pancreatic-bile juice (PBJ) of rats...

The effectiveness and mechanisms of γδ T-cell immunotherapy in lung cancer remain unclear. In this study, we assessed the effects of continuous, low-dose γδ T-cell intervention on lung cancer cells. We cultured γδ T cells with a lung cancer cell line (A549) and replaced the γδ T-cell population every 48 hours. The killing effect of γδ Tcells on A549 cells and the Half-maximal inhibitory concentration (IC50) value were detected by the cholecystokinin octapeptide (CCK-8) method...

The B cell regulator Pax5 consists of multiple domains whose function we analyzed in vivo by deletion in Pax5. While B lymphopoiesis was minimally affected in mice with homozygous deletion of the octapeptide or partial homeodomain, both sequences were required for optimal B cell development. Deletion of the C-terminal regulatory domain 1 (CRD1) interfered with B cell development, while elimination of CRD2 modestly affected B-lymphopoiesis. Deletion of CRD1 and CRD2 arrested B cell development at an uncommitted pro-B cell stage...

Inherited prion diseases caused by two- to twelve-octapeptide repeat insertions (OPRIs) in the prion protein gene (PRNP) show significant clinical heterogeneity. This study describes a family with two new cases with a 4-OPRI mutation and two asymptomatic mutation carriers. The pooled analysis summarizes all cases reported in the literature to date and describes the relation between survival, age of onset, number of OPRI and codon 129 polymorphism. MEDLINE and Google Scholar were queried from database inception up to December 31, 2022...

PEGylation is a commonly used approach to prolong the blood circulation time of cationic liposomes. However, PEGylation is associated with the "PEG dilemma", which hinders binding and uptake into tumor cells. The cleavable PEG products are a possible solution to this problem. In the current research, doxorubicin-loaded cationic liposomes (Dox-CLs) surface-conjugated with a matrix metalloproteinase-2 (MMP-2)-sensitive octapeptide linker-PEG derivative were prepared and compared to non-PEGylated and PEGylated CLs in terms of size, surface charge, drug encapsulation and release, uptake, in vivo pharmacokinetics, and anticancer efficacy...

A carbon nanotube-doped octapeptide self-assembled hydrogel (FEK/C) and a hydrogel-based polycaprolactone PCL composite scaffold (FEK/C3 -S) were developed for cartilage and subchondral bone repair. The composite scaffold demonstrated modulated microstructure, mechanical properties, and conductivity by adjusting CNT concentration. In vitro evaluations showed enhanced cell proliferation, adhesion, and migration of articular cartilage cells, osteoblasts, and bone marrow mesenchymal stem cells. The composite scaffold exhibited good biocompatibility, low haemolysis rate, and high protein absorption capacity...

The chemical evolution of biomolecules was clearly affected by the overall extreme environmental conditions found on Early Earth. Periodic temperature changes inside the Earth's crust may have played a role in the emergence and survival of functional peptides embedded in vesicular compartments. In this study, all-atom molecular dynamic (MD) simulations were used to elucidate the effect of temperature on the properties of functionalized vesicle membranes. A plausible prebiotic system was selected, constituted by a model membrane bilayer from an equimolar mixture of long-chain fatty acids and fatty amines, and an octapeptide, KSPFPFAA, previously identified as an optimized functional peptide in an evolution experiment...

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Noninvasive imaging techniques for the early detection of infections are in high demand. In this study, we present the development of an infection imaging agent consisting of the antimicrobial peptide fragment UBI (31-38) conjugated to the chelator 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA), which allows for labeling with the positron emitter Ga-68. The preclinical evaluation of [68 Ga]Ga-NODAGA-UBI (31-38) was conducted to investigate its potential for imaging bacterial infections caused by Staphylococcus aureus...

Among the toxic metabolites of the fungal world, those that, due to their strong biological effect, can seriously (even fatally) damage the life processes of humans (and certain groups of animals) stand out. Amatoxin-containing mushrooms and the poisonings caused by them stand out from the higher fungi, the mushrooms. There are already historical data and records about such poisonings, but scientific research on the responsible molecules began in the middle of the last century. The goals of this review work are as follows: presentation of the cosmopolitan mushroom species that produce amanitins (which are known from certain genera of four mushroom families), an overview of the chemical structure and specific properties of amanitins, a summary of the analytical methods applicable to them, a presentation of the "medical history" of poisonings, and a summary of the therapeutic methods used so far...

Flavodoxins (Flds) mediate the flux of electrons between oxidoreductases in diverse metabolic pathways. To investigate whether Flds can support electron transfer to a sulfite reductase (SIR) that evolved to couple with a ferredoxin, we evaluated the ability of Flds to transfer electrons from a ferredoxin-NADP reductase (FNR) to a ferredoxin-dependent SIR using growth complementation of an Escherichia coli strain with a sulfur metabolism defect. We show that Flds from cyanobacteria complement this growth defect when coexpressed with an FNR and an SIR that evolved to couple with a plant ferredoxin...

The hypothalamic brain cell types that produce estradiol from testosterone remain unclear. Aromatase inhibition affects ventromedial hypothalamic nucleus (VMN) glucose-stimulatory nitric oxide (NO) and glucose-inhibitory γ-aminobutyric acid (GABA) transmission during insulin (INS)-induced hypoglycemia (IIH). Pure GABA and NO nerve cell samples acquired by laser-catapult-microdissection from consecutive rostro-caudal segments of the VMN were analyzed by Western blot to investigate whether regional subpopulations of each cell type contain machinery for neuro-estradiol synthesis...

In recent years, the application of nanoimaging technology on standardize tumor diagnosis has become a new research hotspot, especially nanoprobes. Our research group has synthesized a kind of nanocarrier, mPEG2000-GPLGIAGQ-DSPE, which has the characteristic of matrix metalloproteinase-2 (MMP2) sensitive ability in tumor microenvironment. Meanwhile, the encapsulation method is adopted to prepare MMP2-sensitive tumor-targeted prussian blue fluorescent nanoprobe with mPEG2000-GPLGIAGQ-DSPE as the carrier. On the one hand, this novel nanoprobe not only can effectively improve the solubility of prussian blue, but is non-toxic and safe for cells...

Neuroendocrine tumors (NETs) of duodenal origin are an unusual subset among all NETs, comprising only about 3% of this neoplasm class. In general, NETs are characterized by overexpression of somatostatin receptors and carry an excellent prognosis with early diagnosis and intervention. Chromogranin A (CgA), a protein originating in secretory vesicles of neurons and endocrine cells, has gained wide usage in NET diagnosis and surveillance. Lanreotide is a synthetic octapeptide somatostatin analog with potent anti-proliferative action which has been approved by the FDA (U...

Self-Assembled short peptide-based hydrogel platform has become widely applicable biomedical therapeutic maneuver for their soft, tunable architecture which can influence cellular behavior and morphology to an inordinate extent. Here in this work, a short supramolecular hydrogelator peptide has been designed using a fusion approach: from the C-terminus conserved "FFGLM" section of biologically abundant neuropeptide: Substance P. In addition to this to incorporate a good hydrophobic-hydrophilic balance, the truncated pentapeptide segment was further C-terminally modified by the incorporation of an integrin-binding "RGD" motif...

Renovascular hypertension (RVH) is a secondary form of high blood pressure resulting from impaired blood flow to the kidneys with subsequent activation of the renin-angiotensin-aldosterone system. Often, this occurs due to abnormally small, narrowed, or blocked blood vessels supplying one or both kidneys (ie: renal artery occlusive disease) and is correctable. Juxtaglomerular cells release renin in response to decreased pressure, which in turn catalyzes the cleavage of circulating angiotensinogen synthesized by the liver to the decapeptide angiotensin I...