Peptides

<p>Orexin-A (also known as hypocretin-1) is a hypothalamic neuropeptide that regulates feeding behaviour, reward processes, cognition, the sleep-wake cycle and stress. Orexin-A is involved in stress induced mental illness such as major depressive disorder and anxiety disorders and may therefore be a potential target for treatment of these conditions.Orexins are excitatory neuropeptides generated from the prepro-orexin precursor that is exclusively localised in cells of the lateral and posterior hypothalamic region. Orexins are also widely expressed in human and mammalian retinas, such as bipolar cells, amacrine cells and ganglion cells.Orexin-A activates the orphan G-protein-coupled orexin receptor, type 1 (OX1R) and 2 (OX2R). There are approximately 10,000-20,000 orexinergic neurons in the human brain.</p>

<p>LP2</p>

<p>The SARS-CoV-2 non-structural protein 13 (NSP13) has been identified as a target for anti-viral therapeutics due to its highly conserved sequence and is essential for viral replication.  NSP13 is part of the helicase superfamily 1B. As an NTPase and RNA helicase, NSP13 binds to RNA-dependent RNA polymerase and acts in concert with the replication-transcription complex to stimulate backtracking and further activate NSP13 helicase activity. These factors make NSP13 a good target for developing new antiviral drugs. In addition, the identification of epitopes within the NSP13 sequence can help design more effective SARS-CoV-2 vaccines.Models have predicted epitopes exhibiting antigenicity, stability and interactions with MHC class-I and class-II molecules. NSP13 (556-570) is an epitope candidate with various HLA restrictions. This epitope can be used to better vaccine design for more durable CD4+ and CD8+ T cell responses for long-lasting immunity.</p>

<p>Pantinin-3, like other pantinin peptides, has high activity against Gram-positive bacteria yet weak activity against Gram-negative bacteria. With the exception of S. aureus, pantinin-3 displays the highest activity against all Gram-negative bacteria for which it has been tested. Pantinin-3 also displays activity against Candida tropicalis and has relatively mild haemolytic activity against human red blood cells.</p>

<p>HLA-A*02 is a class I major histocompatibility complex (MHC) allele which is part of the HLA-A group of human major histocompatibility complex (MHC) leukocyte antigens (HLA). HLA-A is a human MHC class I cell surface receptor and is involved in presenting short polypeptides to the immune system. These polypeptides are typically 7-11 amino acids in length and originate from proteins being expressed by the cell. Cytotoxic T cells in the blood "read" the peptide presented by the complex and should only bind to non-self peptides. If binding occurs, a series of events is initiated culminating in cell death via apoptosis. Hepatitis B virus (HBV) polymerase is a multifunctional enzyme that can use both RNA and DNA as a template for amplification and also has an RNase H function. First the polymerase acts on the HBV pre-genomic RNA (pgRNA) to reverse transcribe it to form the (-) DNA strand. Simultaneously the RNA template is degraded by the polymerases RNase H activity, except for a stretch of RNA at 5' end of the pgRNA which is used to prime the synthesis of the (+) DNA strand. This process results in a new partially double-stranded relaxed circular DNA molecule (rcDNA) within a new capsid.</p>

<p>Residues 1-16 of the gastrointestinal hormone motilin, secreted from endocrine cells in the small intestines, mainly from the jejunum and duodenum, in response to the fasting, drinking water or the mechanical stimulus of eating.</p>

<p>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 TQAFGRRGPEQTQGN (271-285) 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.</p>

<p>Boc-VPR-AMC is a fluorogenic peptide substrate composed of the short peptide chain, Valine-Proline-Arginine (VPR) and the fluorophore, 7-amino-4-methlycoumarin (AMC). Fluorogenic peptide substrates such as Boc-VPR-AMC have high sensitivity and specificity and therefore can be used to detect molecules of interest. For example within the field of scientific forensics, Boc-VPR-AMC can be used to investigate deposits of saliva in situ. When Fluorogenic peptide substrates are incubated with specific enzymes, fluorescence is emitted due to the release of the fluorophore from the peptide-fluorophore bond. When Boc-APR-AMC interacts with its target enzyme, the 7-amino-4-methylcoumarin fluorophore is released causing a fluorescent emission at 440nm.</p>

<p>[Nle12] alpha-factor is a cyclic analog of the Saccharomyces cerevisiae alpha-factor mating pheromone.</p>

<p>GQPR tetrapeptide.</p>

<p>Interactions between ECM proteins and growth factors were only thought to concentrate growth factors and to enhance their multimerisation for signalling. However, recent studies indicate that binding of growth factors to ECM proteins may enhance interactions between multi-domain ECM proteins, such as fibronectin (FN), with cell surface receptors, mostly integrins. The discovery of P12 revealed that a small peptide can mimic the role of FN with PDGF-BB, suggesting that some ECM-growth factor interactions may be less complex. P12 can not only bind to PDGF-BB, but also promote cell survival and improve rat skin burns in a dose dependent manner.P12 may have a clinical potential, especially in the reduction of cell death after tissue damage.</p>

<p>The MHC class II allele I-Ag7 is the allele associated with diabetes in the non-obese diabetic (NOD) mouse. I-Ag7 is also associated with spontaneous mouse models of arthritis and multiple sclerosis. The peptide mimotope mimics the structure of an epitope and therefore causes an antibody response similar to the one elicited by the epitope.</p>

<p>Antagonist peptide of VEGF-A and VEGF-B reproducing two binding regions of VEGF-B (loop 1 and loop3) linked together by a receptor binding region of VEGF-A (loop3). Binds to both VEGFR1 and VEGFR2 and inhibits VEGF-A driven proliferation, migration and tube formation in HUVECs.</p>

<p>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 GMEVTPSGTWLTYTG (321-335) 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.</p>

<p>JAG-1(188-204). Jagged - 1 is a cell surface ligand for in the Notch pathway. Notch receptors and ligands are present on the extracellular service of cells and require cell-cell contact for engagement. Ligand binding to Notch receptors results in the proteolytic cleavage of membrane-bound Notch receptors, thus allowing the intercellular region to be transported to the nucleus and become a transcriptional activator. The ligand-induced Notch activation is regulated by E3 ubiquitin ligases, Mindbomb1 (Mib-1) and Neuralized.JAG1 is widely expressed throughout mammalian development, across many tissues and developmental stages. Notch signalling plays a critical role in cellular fate determination including muscle cell differentiation, neurogenesis, and the development of the sensory regions of the inner ear- heart- kidney- eye- lung and other tissues.Jag-1 has been implicated in breast- cervical- colorectal- endometrial- gastric- head and neck- ovarian- hepatocellular- lung- pancreatic- prostate, and kidney and adrenocortical cancers, leukemia and lymphoma. Co-overexpression of Notch-1 and Jagged-1 predicts the poorest overall cancer survival. JAG1 mutations have also been associated Alagille syndrome.</p>

<p>SARS-CoV-2 Nucleoprotein (331-345)</p>

<p>[5-FAM]-ERKtide</p>

This peptide is derived from gliadin wheat protein residues 31-43. It elicits an innate immune response by upregulating expression of interleukin (IL)-15 and cyclooxygenase (COX)-2. This peptide also promotes expression of CD25 on monocytes and macrophages, expression of CD83 on dendritic cells, and p38 MAP kinase activation. Treatment with this peptide allows immunodominant epitopes (57-68 and 62-75) to induce T-cell activation and enterocyte apoptosis.

<p>Reactivity to human leukocyte antigens (HLAs) is a rising concern in clinical treatments such as organ transplant rejection. Understanding the epitopes and the signalling pathways leading to reactivity could produce better clinical therapies in the future. The peptides presented by the non-classical HLA-G are important for a largely tolerogenic role and are considered part of an immune checkpoint. This, therefore, makes understanding ligand characteristics and HLA-G a target for cancer therapies. Interleukin-27 subunit β (22-30) fragment has been identified as an epitope that human leukocyte antigen HLA-G naturally presents, determined by liquid chromatographic tandem mass spectrometry (LC-MS/MS). This epitope has been used extensively in the literature to help understand the natural ligand presentation of HLA-G.For example, leukocyte immunoglobulin (Ig)-like receptors (LILRs) are key regulators of the immune response and therefore targets for therapeutics. Inhibitory LILRB1 and LILRB2 with HLA-G are pivotal for immunotolerance during pregnancy and autoimmune diseases plus cancer cell immune evasion. Interleukin-27 subunit β (22-30) fragment was used in binding affinity assays to clarify the conformational plasticity of the interaction between the receptor, the HLA antigen, and the various peptides HLA-G can accommodate.</p>

<p>AF12198 is a selective receptor antagonist to the human cytokine, type 1 interleukin-1 (IL-1) and thus blocks IL-1β signalling. AF12198 can inhibit IL-1-induced IL-8 production by human dermal fibroblasts and IL-1-induced intercellular adhesion molecule-1 (ICAM-1) expression by endothelial cells. AF12198 also blocks IL-1 induction of IL-6 and down regulates IL-6 induction in monkeys. AF12198 does not bind the human type II IL-1 receptor, or the murine type I IL-1 receptor.IL-1 influences a wide range of immune and inflammatory responses. Sustained expression of even low levels of IL-1 can be harmful in chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease.</p>