Peptídeos

<p>Vasoactive intestinal peptide (VIP) is a neuropeptide found throughout the body and the central nervous system. VIP is located within cell bodies and nerve endings of the enteric nervous system, brain and pancreas. VIP neurons in the peripheral system fire to regulate blood vessels, and the  CNS innervate cerebral vasculature. VIP  binds to G protein-coupled receptors VPAC1 and VPAC2. VIP and VPAC2 are detected in circular smooth muscle cells of cerebral arterioles. VIP and VPAC1 are also found in lymphatic tissue. VIP can block inflammation, modify the Th response favouring Th2 and induce regulatory T cells. Overexpression of each receptor has been linked to various cancers.VIP administration leads to pancreatic bicarbonate-rich fluid secretion but not to the same degree stimulated by secretin. VIP stimulates insulin secretion in a glucose-dependent manner and also stimulates glucagon secretion. Studies have found that in morbidly obese patients, VIP levels are lowered and work to slow gastric and duodenal motility but increase gastric emptying. Therefore, decreasing VIP levels in obese patients may increase weight gain by accelerating gastric emptying.VIP has been well studied in pancreatic acini. VIP is a full agonist of amylase secretion and increases cyclic AMP synchronised with an increase in intracellular Ca2+ triggered by stimuli that act through cholecystokinin (CCK) or cholinergic agonists. Most cAMP increases and amylase secretion appears to be mediated via VPAC1.</p>

<p>Formyl-MIFL-acid.</p>

<p>Neuropeptide S (NPS) is a neuropeptide found in mammalian brains, primarily in neurons in the lateral parabrachial nucleus, the peri-locus coeruleus and the principle sensory 5 nucleus of the trigeminus. NPS in involved in several neuroendocrine, behavioural and inflammatory responses, including: reducing anxiety in mice- suppressing appetite- and inducing wakefulness and hyperactivity. NPS treatment can be used to improve fear extinction in mice and limit fear memory retrieval after fear reduction training, thus making it an interesting target in relation to post-traumatic stress disorder. NPS exerts its actions by binding to a G-protein coupled receptor, NPSR.</p>

<p>Biotin TAT (48-60) is a cell penetrating cationic peptide derived from the N-terminus of the Tat protein, which is a trans-activator of the transcription protein present in the human immunodeficiency virus (HIV). The 48-60 region of the TAT peptide is an arginine-rich bascic domain which as a whole has three domains that function to aid HIV through transactivation, DNA binding and nuclear transport. As a cell penetrating peptide (CPP) TAT aids in the cellular uptake of molecules and hence serves a valuable purpose in transduction methods. This property has been demonstrated through its ability of allowing toxins such as the neurotoxin Botulinum neurotoxin Type A, produced by the Clostridium botulinum type A bacteria to penetrate the skin barrier non-invasively.This peptide has a covalently bonded N-terminal Biotin tag that can be used for detection and purification and contains an N-terminal aminohexanoic acid spacer (Ahx).</p>

<p>EHD1 is a member of the C-terminal EPS15-Homology Domain-containing (EHD) protein family and is involved in recycling cell surface receptors.</p>

<p>Substrate peptide for Scr, tyrosine kinase, for use in in vitro assays for Src activity.Src is a member of the Src Family tyrosine Kinases (SFKs), a large cytosolic, non-receptor, kinase family that controls multiple signalling pathways in animal cells. Src is a tyrosine kinase proto-oncogene and elevated levels of Src protein are seen in different tumours including: breast- lung- thyroid- glioblastoma- colorectal- pancreatic- prostate- gastric- biliary tract and skin cancer. Src levels are often associated with tumour progression, metastasis, and a poor clinical outcome and therefore Src has been investigated as a therapeutic target.Peptide is labelled with an N-terminal 5-carboxyfluorescein (5-FAM), a widely used green fluorescent tag.</p>

<p>Endogenous peptide GPR83 agonist derived from processing of precursor protein, proSAAS, a 26-kDa protein encoded by the PCSK1N gene (chromosomal localization Xp11.3 in humans). It is widely expressed in a number of species where it is involved in feeding, stress modulation and addiction and reward circuits.</p>

<p>Peptide derived from tumour necrosis factor alpha (TNF-α), a cytokine produced by macrophages, T lymphocytes and natural killer cells. It exerts its function through targeting the transmembrane receptors TNF receptor 1 and TNF receptor 2, the latter of which it has a higher affinity for. When binding to TNF receptor 1 TNF-alpha is pro-apoptotic and when binding to TNF receptor 2 it is anti-apoptotic. TNF-α has further roles in inflammation, immunity and cancer.Expression of the TNF-α gene, located on chromosome 6 in humans is regulated by factors such as nuclear factor kappa b (NFKB).Dysregulation of TNF-α and its receptors can contribute to diseases such as rheumatoid arthritis, Crohn disease and diabetes. Anti-TNF-α can be used as a therapeutic agent to target TNF-α during inflammatory diseases.</p>

<p>Histone H3 (30-41) K36Me2 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 (30-41) lysine 36 has been dimethylated.</p>

<p>Cyclo(CLLFVY) is a cyclic peptide which binds to the PAS-B domain of HIF-1alpha, thus inhibiting HIF-1 dimerisation and HIF-1 mediated hypoxia signalling.</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 LSPRWYFYYLGTGPEAGL (104-121) 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>Cell penetrating peptide with a repeating motif of cationic-nonpolar-cationic (C-N-C) residues, such repeating motifs are important features of membrane-penetrating peptides. This peptide is able to enhance the efficacy and uptake of peptide phosphorodiamidate morpholino oligomers (PPMOs) into bacterial cells. PPMOs are synthetic DNA mimics that bind cRNA and inhibit bacterial gene expression, however these antisense oligomers need help crossing the outer membrane of Gram-negative bacteria due to their molecular weight and polar characteristics. Cell penetrating peptide such as this, when attached to antisense oligomers can improve their entry into Gram-negative bacteria and increased their potency by orders of magnitude.</p>

<p>Acetly-Claudin-6 is derived from the tight junction protein Claudin-6 which is encoded by the CLDN6 gene and can be found within epithelial cell to cell contacts. The Claudin family are transmembrane proteins containing two extracellular loops and are involved in maintaining cell polarity and controlling paracellular ion flux.The expression of Claudin-6 is most commonly seen in early embryonic development where it plays a role in the regulation of blastocyst formation through tight junction enhancement. It is also an important factor for epidermal differentiation and barrier formation. Although it is more commonly seen in embryonic development it is also expressed in mammary epithelial cells. Studies have also shown Cldn6 to be a tumour suppressor in breast cancer.</p>

<p>Apelin-36 (human) is derived from the apelin peptide which acts as a ligand for the apelin receptor (APJ) G protein coupled receptor and is a substrate for angiotensin converting enzyme 2. Preprapelin, encoded for by APLN located on Xq25-26.1, is cleaved to form either apelin 36, apelin 17, apelin 13, or apelin 12. As a member of the adipokine hormone family, which are involved in processes such as vascular homeostasis and angiogenesis, apelin is secreted from adipose tissue.Both apelin and the apelin receptor are widely distributed around the body thus apelin has been found to be associated with cardiovascular diseases, obesity, diabetes and cancer. Studies exploring myocardial infarction showed there to be greater apelin mRNA expression during human heart failure compared to in healthy tissue. Apelin protects against heart failure due to, the pyroglutamyl form of apelin, playing a role in decreasing infarct size of myocardial infarctions. Furthermore in rats with hypertension, the expression of apelin and APJ was decreased.</p>

<p>Mammalian bombesin-like neuropeptide- first isolated from pig spinal cord, which can stimulate rat uterine smooth muscle contraction and gastrin and somatostatin secretion in vitro. Increases blood pressure and pancreatic exocrine secretion in dogs.</p>

<p>Heat shock protein gp96 inhibitor which binds to and antagonizes gp96 mediated lipopolysaccharide (LPS) induced cytokine production. Anti-inflammatory in a number of in vivo and in vitro models.</p>

<p>β-Amyloid 1-12 (Aβ1-12) is one of many short Aβ species found in vivo and is formed by the cleavage of amyloid β precursor protein by β- and α-secretase. Amyloid β-protein (Aβ) has been identified as the key subunit of the extracellular plaques found in the brains of patients with Alzheimer disease (AD) and Down 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 α-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.-Biotin is C-terminally linked to the peptide via ethylenediamine for convenient detection and purification. Alternative β-Amyloid fragments and labels are also available, please refer to our peptide catalogue for availability.</p>

<p>An immunoreceptor tyrosine-based activation motif (ITAM) is a phosphorylation site consisting of a conserved sequence of four amino acids that is repeated twice in the cytoplasmic tails of cell-surface non-catalytic tyrosine-phosphorylated receptors. The major role of ITAMs is its involvement in the initiation of signalling pathway and the subsequent activation of immune cells. The motif has the following structure: YxxL/I. where xx are any two amino acids. Two of these signatures are typically separated by between 6 and 8 amino acids in the cytoplasmic tail of the molecule (YxxL/Ix(6-8)YxxL/I). ITAMs are found in the CD3 and θ¶-chains of the T cell receptor (TCR) complex. TCR is a multi-subunit receptor on the surface of T cells. TCR contains two ligand binding chains containing 20 phosphorylation sites, distributed on 10 ITAMs. The TCR θ¶-chain is a homodimer subunit that contains six ITAMs (12 sites). These sites are phosphorylated by the membrane-anchored Src family tyrosine kinase Lck and Fyn and are dephosphorylated by the transmembrane phosphatases CD148 and CD45. When both tyrosines in an ITAM are phosphorylated they generate docking sites for the tandem SH2 domains of the cytosolic tyrosine kinase ZAP-70. Bound ZAP-70 can phosphorylate tyrosines on other substrates that initiate the signal transduction that leads to T cell activation. The multiple ITAMs on the TCR function mainly to amplify subsequent signalling.T cells rely on the TCR to recognize antigens, in the form of peptides bound to major histocompatibility complexes (MHC), on the surfaces of antigen-presenting cells. Binding of TCR to antigen-MCH complexes leads to proliferation, differentiation, and the secretion of effector cytokines, contributing to the elimination of infections.</p>

<p>Human adrenocorticotropic hormone (ACTH), also known as corticotropin, is a tropic hormone produced and secreted by the anterior pituitary gland and member of the melanocortins peptide family. ACTH is cleaved from the precursor proopiomelanocortin (POMC). ACTH is an important component of the hypothalamic-pituitary-adrenal (HPA) axis and is often produced in response to biological stress. ACTH acts to increase the production and release of cortisol via its interaction with the ACTH receptor- ACTHR, also known as melanocortin type 2 receptor (MC2R). Receptor activation increases the intracellular concentration of cAMP via adenylyl cyclase.Abnormal ACTH levels in the body has been linked to primary adrenal insufficiency/Addison's disease, Cushing's disease and secondary adrenal insufficiency. ACTH (15-24) has been shown to be a competitive ACTH receptor antagonist and can be used as a method to combat the overproduction of cortisol. Treatment with ACTH (15-24) inhibits activation of a specific melanocortin 2 receptor (MC2R) by inhibiting adrenocorticotropin hormone (ACTH)-induced production of cortisol. ACTH (15-24) is provided here with a C-terminal cysteine residue for conjugation reactions.</p>

<p>Apidaecin IB was isolated from the honeybee Apis mellifera. As a cationic proline-rich antimicrobial peptide (PrAMP), Apidaecin IB shows sequence homology with drosocin but is devoid of any pore-forming activity. Apidaecin IB is most active against gram-negative bacteria, it can navigate the outer membrane to the periplasm and then to the cytoplasm. Apidaecin IB is a non-lytic AMP, the main target of its antimicrobial activity appears to be inhibition of the chaperone heat shock protein DnaK. Toxicity appears to be exclusively to bacteria and thus has been trialled as a treatment for systemic bacterial infections. Numerous analogues and derivatives are being investigated to establish Apidaecin IB mode of action and also to improve its functionality.</p>