Péptidos

Histone H3 (20-39)-Biotin is derived from Histone 3 (H3) which is one of the four core histones (H2A, H2B, H3 and H4) fundamental in compacting eukaryotic DNA into the nucleosome. The nucleosome arises when 147 base pairs of DNA wrap around a H3-H4 tetramer and two H2A-H2B dimers, forming the histone octamer core. Both H4 and H3 are highly conserved and perform roles in binding to segments of DNA which enter and leave the nucleosome and in chromatin formation. Similar to the other core histone, H3 has a globular domain and a flexible N-terminal domain, 'histone tail' which can undergo modifications such as acetylation, methylation, phosphorylation and ubiquitination. Due to histones containing a large number of lysine and arginine residues they have a positive net charge which interacts in an electrostatic manner with the negatively charged phosphate groups in DNA. The transcriptional activation or silencing of the chromatin is controlled by ATP-dependent chromatin remodelling factors and histone modifying enzymes which target histone proteins. Both processes function to alter the positioning of the nucleosome, allowing the DNA it to be either available or inaccessible to the transcription machinery.Another modification process histones can undergo is biotinylation where the covalent attachment of a biotin molecule is catalysed by the enzyme Biotinidase. This cleaves biocytin to generate a biotinyl-thiester intermediate. The biotinyl can then be transferred onto the histone lysine ɛ-amino group which is covalently attached to Histone 3. Overall the biotinylation sites identified in histone 3 are: K4, K9 and K18. The presence of biotinylated histones have been detected in human cells such as lymphocytes and lymphomas.

Ghrelin is involved in several physiological processes, including feeding and lipid accumulation, stress response, anxiety, cardiac performance, immunity and inflammation, taste sensation, reward-seeking behaviour, regulation of glucose metabolism and thermogenesis, memory, motivation and learning.Ghrelin is a peptide hormone that typically has a serine at the third residue and relies on modification with a fatty acid to give ghrelin its functional activity. In its modified form, ghrelin is an endogenous ligand for the pituitary gland's growth hormone receptor (GHS-R) and stimulates growth hormone release.Ghrelin acts on the hypothalamic arcuate nucleus as an orexigenic agent to stimulate appetite. Ghrelin is produced in the stomach as a precursor peptide preproghrelin, cleaved to ghrelin. Ghrelin circulates in the blood and can cross the blood-brain barrier. Levels of ghrelin respond to fasting conditions and allow signals about the energy status to be transmitted from the peripheral organs to the central nervous system to maintain energy homeostasis.Ghrelin is a valuable target for treating conditions such as anorexia, cachexia, sarcopenia, cardiopathy, neurodegenerative disorders, renal and pulmonary disease, gastrointestinal disorders, inflammatory disorders and metabolic syndrome.

Portion of EBV

Autocamtide-2

a-Gliadin (229-246) is derived from Gliadin peptides, the component of wheat involved in the gastrointestinal symptoms of wheat allergy and Celiac Disease (CD). During wheat allergies histamines and leukotrienes are secreted due to gliadin peptide sequences cross-linking two IgE molecules on mast cells and basophils.The glutamine and proline rich peptides of which Gliadin is composed of are resistant to proteolysis during digestion, leaving them active in the gastrointestinal tract. Subsequently these are deamidated by tissue transglutaminase and can bind to HLA-DQ2 or DQ8. As a result in patients with the autoimmune disease CD, there is a Th1-mediated inflammatory immune response against these gliadin peptides.Gliadin can exert additional effects on the intestinal microbiota and ileal barrier function. It has been found that gut microbiota members such as Bifidobacterium and lactobacillus have the ability to digest and inactivate gliadin peptides hence reducing their inflammatory effects in the gastrointestinal system.

Amyloid β-peptide (Aβ) has been identified as the key subunit of the extracellular plaques found in the brains of patients with Alzheimer's disease (AD) and Down's syndrome (DS). Aβ has therefore been extensively studied as a potential target for treatment of AD. Aβ is formed from the cleavage of the large, transmembrane protein APP (amyloid precursor protein). Cleavage of APP by β- and then γ-secretases results in the formation of Aβ. Aβ can aggregate to produce amyloid-β oligomers, which are thought to be highly neurotoxic. Over time Aβ can further aggregate to produce the characteristic senile plaques present in AD and DS. Aβ can be degraded by enzymes such as neprilysin, insulin degrading enzyme or endothelin converting enzyme. At physiological levels Aβ may be involved in controlling synaptic activity and neuronal survival.

Peptide LCBiot-CGFECVRQCPERC-NH2 is a Research Peptide with significant interest within the field academic and medical research. This peptide is available for purchase at Cymit Quimica in multiple sizes and with a specification of your choice.

GRGDS peptide

Peptide obtained by linking the 11 amino acid human HIV Tat transporter to a 21 amino acid sequence corresponding to the ADAM10 proline-rich domains.

Mucin 10 (153 - 165), EA2.

VP4 is a viral coat protein of Nora virus encoded for by ORF4. The product of this gene is likely cleaved into three capsid proteins, VP4A, B and C. VP4 is also the most conserved gene from Nora virus and related viruses. Nora virus is a non-pathogenic virus found in gut of Drosophila melanogaster. It causes persistent, non-pathological infection, it replicates in the fly gut and is transmitted via the faecal-oral route. Nora virus has a 12333 nucleotides long single-stranded RNA genome of positive polarity.

The Histone H3 (22-30)-K27Me3 is derived from Histone 3 (H3) which is one of the four core histones (H2A, H2B, H3 and H4) fundamental in compacting eukaryotic DNA into the nucleosome. The nucleosome arises when 147 base pairs of DNA wrap around a H3-H4 tetramer and two H2A-H2B dimers, forming the histone octamer core. Both H4 and H3 are highly conserved and perform roles in binding to segments of DNA which enter and leave the nucleosome and in chromatin formation. Similar to the other core histone, H3 has a globular domain and a flexible N-terminal domain, 'histone tail' which can undergo modifications such as acetylation, methylation, phosphorylation and ubiquitination. Due to histones containing a large number of lysine and arginine residues they have a positive net charge which interacts in an electrostatic manner with the negatively charged phosphate groups in DNA. The transcriptional activation or silencing of the chromatin is controlled by ATP-dependent chromatin remodelling factors and histone modifying enzymes which target histone proteins. Both processes function to alter to change the positioning of the nucleosome, allowing the DNA it to be either available to the transcription machinery or inaccessible.The Histone H3 (20-36) lysine 27 has been trimethylated which is usually a marker of repressive chromatin. H3K27 trimethylation also prevents H3 from interacting with SET1-like complexes, thus inhibiting the trimethylation of H3K4.

The SARS-CoV-2 spike protein is present on the outside of the virus particles and can bind to angiotensin-converting enzyme II (ACE2) present on the host cells. The C-terminal receptor binding domain (RBD) of the spike protein binds to the N-terminal peptidase M2 domain of ACE2. This receptor binding results in the internalisation of the virus-receptor complex and is, therefore the mechanism of entry of SARS-CoV-2 into host cells.The spike protein residues VQIDRLITGR (991-1000) from SARS-CoV-2 have been identified as a T-cell epitope with a predicted HLA restriction. Immune targeting of confirmed epitopes may potentially offer protection against SARS-CoV-2 and help the development of vaccines for long-lasting immunity.

This insulin B-chain peptide binds to a class II histocompatibility complex (MHC) allele called I-Ag7. A number of autoimmune diseases has been linked to class II proteins encoded by the MHC. Type 1 diabetes, or insulin-dependent diabetes mellitus, is a T cell-mediated disease that results in autoimmune destruction of pancreatic ß cells leading to hyperglycemia. This insulin β peptide may be a self-antigen candidate that could initiate the disease. Immunisation with this peptide in mice led to autoantibodies and insulitis. In the non-obese diabetic (NOD) mouse model, this peptide represents the dominant insulin peptide driving disease initiation.Insulin is a polypeptide composed of two peptide chains referred to as the alpha chain and β chain. Insulin is normally secreted rapidly from the β-cells of the pancreatic islets in response to nutrients absorbed after a meal. In type 1 diabetes mellitus, there may be an absolute insulin deficiency as a consequence of autoimmune destruction of the β-cells.

Forms of inherited muscular dystrophy such as Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) result from mutations targeting the dystrophin gene. These disorders are X-linked, progressive, and cause the gradual weakening of the muscles leading to respiratory failure and ultimately reduces the patient lifespan.In DMD, mutations lead to the production of premature stop codons and hence the truncated dystrophin protein product is vulnerable to nonsense mediated decay and degradation. Therefore, dystrophin production in muscle cells is reduced. On the other hand, nonsense mutations which also contribute to DMD, cause exon skipping in BMD and result in an internally truncated protein product which are partially functional. The symptoms of BMD are later onset compared with DMD which develop in patients between 2 to 7 years.Treatments of dystrophin disorders are in clinical trials including antisense oligonucleotide exon skipping and gene therapy. However, the efficacies of these treatments are not easily quantified. Currently levels of muscular dystrophin are quantified by western blot which can be unreliable. The peptide provided here, aligning residues dystrophin (50-61), has been used to try and create a quantifiable method that is reproducible. The method used was not successful, but dystrophin (50-61) remains a useful tool to create a potential quantification method for diagnosis and progress of dystrophin disorders as it was effectively detected by mass spectrometry and Western blot. Within our catalogue we also have other peptides tested for dystrophin quantification available plus the full-length dystrophin protein.

The coronavirus (CoV) nucleoprotein is the major component of CoV structural proteins. The nucleoprotein has a critical role in virus assembly and RNA transcription. The nucleoprotein is essential in the formation of helical ribonucleoproteins and in regulating viral RNA synthesis. The nucleoprotein can also regulate infected host cellular mechanisms. It is highly expressed during infection and may induce protective immune responses against SARS-CoV and SARS-CoV-2.The nucleoprotein residues FKDQVILLNKHIDAY (346-360) from SARS-CoV-2 have been identified as a T-cell epitope with a predicted HLA restriction. Immune targeting of confirmed epitopes may potentially offer protection against SARS-CoV-2 and help the development of vaccines for long-lasting immunity.

Insulin is a polypeptide composed of two peptide chains referred to as the alpha chain and β chain. These chains are linked by two disulphide bonds, and an additional disulphide is formed within the alpha chain. In most species, the alpha chain consists of 21 amino acids and the β chain of 30 amino acids. Insulin is normally secreted rapidly from the β-cells of the pancreatic islets in response to nutrients absorbed after a meal. In type 1 diabetes mellitus, there may be an absolute insulin deficiency as a consequence of autoimmune destruction of the β-cells. On the other hand, in type 2 diabetes mellitus, insulin secretion is impaired and is inadequate to overcome peripheral insulin resistance.

Venom peptidomes and proteomes have the potential for significant inroads to novel drug discovery. The non-disulphide bridge peptides (NDBPs) have become a particular focus due to their large range of apparent structures and biological activity while retaining high specificity. Additionally, it has been found that a few site-specific modifications or post-translational modifications can have significant impacts on the potency of their biological effects.Within the peptidome AcrAP1 was identified in the NDBP as having antimicrobial and bactericidal activity. The nascent peptide contains a predicted hydrophobic region, this was altered to lysine residues generating a hydrophilic region, AcrAP1a. This cationic enhancement markedly increases their antibacterial potency against bacteria and yeast. Furthermore, at relatively high concentrations, it inhibited proliferation of several cancer cell lines but at low concentrations in 2 cell lines the growth was significantly promoted. The duality of AcrAP1a on growth modulation in cancer cell lines as well as having potent antimicrobial activity suggests it is a useful analogue for further research in bacteria and eukaryotes.

Panx-1 mimetic inhibitory peptide that blocks pannexin-1 gap junctions. Inhibits P2X7-mediated dye uptake, ATP-mediated IL-1β release and caspase-1 activation without altering membrane current in macrophages. It can also block activation of NMDA receptor secondary currents.

CMV pp65 (415-429) (HLA-B7) is a CEF (cytomegalovirus, Epstein-Barr virus, and influenza virus) control peptide that is derived from the Cytomegalovirus (CMV). CMV is capable of infecting a wide range of human cell types, where the body's primary immune response to CMV is innate, and relies on inflammatory cytokines and costimulatory molecules in order to control the spread of the virus. CMV pp65 (415-429) (HLA-B7) is defined as a CEF control peptide due to its antigenic properties. Clinically, these peptides are suitable epitopes for CD8+ T cells and can be used to stimulate the release of IFNg. HLA-B7 refers to the cell HLA type that this peptide acts on.

The biologically active C-terminal region of human Kisspeptin. Kisspeptin, is cleaved from a 145 amino acid precursor to a 54 amino acid peptide in humans and a 52 amino acid peptide in mice. Smaller isoforms of 14, 13 and 10 amino acids have also been isolated, each sharing the common C-terminal sequence. Kisspeptin-10 (KP-10) is the most potent member of the kisspeptin family and the plasma half-life of is approximately 6 fold shorter than KP-54. KP-10 is produced by the trophoblast cells in the first trimester of pregnancy and inhibits cell migration primary trophoblasts which is essential for placental invasion.Kisspeptin, a product of the KISS1 gene, is a hypothalamic neuropeptide that stimulates gonadotropin-releasing hormone (GNRH) neurons and drives fertility. Kisspeptin binds specifically to the G-protein-coupled receptor-54, now known as Kiss1r, which is expressed in almost all GNRH neurons. Kiss1r is also expressed in other areas of the brain and periphery, highlighting other possible roles for kisspeptin outside of reproduction.

3CLpro are the key enzymes required by coronaviruses to replicate. They cleave polyproteins to form replicase. This makes 3CLpro a drug target for protease inhibitors with particular interest to COVID-19. For, example Paxlovid®- has been brought to market as a 3CLpro inhibitor that can be administered orally to reduce coronavirus disease 19 (COVID-19) hospitalisation. Aiming to expand on such advances, synthesis of more substrates for 3CLpro are being generated and tested for their ability to inhibit the protease activity and thus replication cycle of coronaviruses. This product is the natural substrate for 3CLpro, this makes it a useful tool as a control but also for structural manipulation to design inhibitors.