Peptides

Ac-Arg-Gly-Lys-AMC trifluoroacetate salt is a fine chemical that is used as a building block in the synthesis of complex compounds. Ac-Arg-Gly-Lys-AMC trifluoroacetate salt has been used as a reagent, speciality chemical and intermediate in research projects. Ac-Arg-Gly-Lys-AMC trifluoroacetate salt can be used to produce useful scaffolds for medicinal chemistry studies.

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.

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.

Fmoc-Thr(tBu)-OH is an amino acid that is used for the synthesis of amides and esters. It is prepared by the solid-phase synthesis of 2,6-dichloroacetic acid and Fmoc-protected thiomorpholine. The product can be purified by a combination of saponification and trifluoroacetic acid hydrolysis. This amino acid has acidic properties, which may be due to its ability to form ester or amide bonds with other compounds in the presence of a base.

Mucin 10 (153 - 165), EA2.

Part of the angiopep family of peptides which have been derived from the Kunitz domain of human aprotinin. These peptides are able to cross the blood brain barrier (BBB) and have been used to facilitate the delivery of pharmacological agents to the brain, for example to target glioblastoma tumours and recurrent brain metastases of pre-treated breast cancers. Angiopep-2 has higher transcytosis capacity and higher brain volume of distribution than aprotinin. Like aprotinin, angiopep-2 interacts with low-density lipoprotein receptor-related protein 1 (LRP1) which is thought to promote its delivery across the BBB via receptor-mediated transcytosis (RMT). However the interaction with LRP1 may not be the only method for angiopep-2 to cross into the brain.

Albumin (556-564) Bovine is derived from the globular protein Albumin and is found in the blood plasma of humans (known as Human Serum Albumin, HSA) where it serves to maintain plasma pressure and nutritional balance. Another role it carries out is the transportation of bound molecules through the blood. Bovine serum albumin (BSA), composed of 583 amino acids, is very similar to HSA thus allowing BSA to be used as a successful model and a standard protein in laboratory experiments.Although BSA and HAS share homology in their three domains, I, II and III, BSA contains 2 tryptophan whereas HAS only contains 1 tryptophan residue.In agriculture the presence of the albumin protein has been used to assess the health of cows to ensure that a suitable quality of milk and meat are produced. Moreover it is important to detect bovine albumin in food and pharmaceutical products due to it being an allergenic protein.

The blood-brain barrier (BBB) is a major obstacle to drug delivery into the central nervous system (CNS), in particular for macromolecules such as peptides and proteins. However, certain macromolecules can reach the CNS via a receptor-mediated transcytosis (RMT) pathway, and low-density lipoprotein receptor-related protein 1 (LRP1) is one of the promising receptors for RMT. Recent studies have shown that biotinylated L57 binds to LRP1 (CL4)-Fc more efficiently than Angiopep-7 (a different LRP1 ligand), which might explain the improved BBB permeability of L57.

Ova (323-339) is an epitope of interest from egg white albumen, which is widely used in allergy research. Ovalbumin is a glycoprotein that is sufficiently large and complex to be mildly immunogenic. It has been demonstrated that ovalbumin contains B-cell epitopes which are recognized by specific IgE antibodies, and CD4 T cell epitopes restricted by the MHC I-Ad molecule in mice and by HLA-D molecule in human.OVA (323-339) can be used to study binding of class II MHC-peptide and T-cell activation in PBMCs by ELISPOT assays. This method quantifies peptide-epitope specificity and IFN-γ releasing effector cells. It has been shown that OVA (323-339) was responsible for 25-35% of T-cell response of isolated BALB/c mouse. An investigation has demonstrated that OVA and OVA (323-339) induced similar lung inflammation and a Th2-like dominant immune response in mouse model.

β-Amyloid 1-13 (Aβ1-13) 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.

Ghrelin is an orexigenic peptide hormone mainly produced in the stomach as precursor preproghrelin. Cleavage of preproghrelin followed by modification leads to the formation of ghrelin with the addition of a fatty acid to its serine 3 residue- ghrelin is capable of activating the growth hormone release receptor (GHSR). Ghrelin is involved in appetite stimulation and growth hormone release.Most circulating ghrelin is in the non-acylated form (des-octanoyl) ghrelin. (Des-octanoyl)-ghrelin has some distinct functions from ghrelin, the lack of acylation prevents binding to the ghrelin receptor and growth hormone release. However, (des-octanoyl) ghrelin has negative inotropic effects on papillary muscle and cardioprotective function. There is evidence (des-octanoyl) ghrelin inhibits proliferation of certain cancer cell lines, while promoting adipogenesis has been observed in other experiments in vivo.

Neuropeptide involved in the regulation of numerous physiological functions. The Galanin agonist with a very high affinity for the hippocampal galanin receptor.

SARS-CoV-2 NSP7 is part of the RNA-dependent RNA polymerase heterotetramer for mediating coronavirus RNA synthesis. NSP7 and NSP8 form a channel to confer processivity on RNA polymerase. NSP7 aids in stabilising NSP12 regions involved in RNA binding and is essential for a highly active NSP12 polymerase complex. These factors make NSP7 a good target for developing new antiviral drugs. In addition, the identification of epitopes within the NSP7 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. NSP7 (26-40) 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.

Cyclic DAG peptide targets connective tissue growth factor (CTGF/CCN2), present in the extracellular matrix, endothelial cells and overexpressed in several brain diseases. CTGF is a matricellular protein that acts as a regulator of several cellular functions, including cell adhesion, migration, mitogenesis, differentiation, and survival. CTGF is up regulated in Alzheimer's disease, Parkinson's disease, brain injury, glioblastoma, and cerebral infarction.DAG peptide has been shown to home to the brain in mouse models of glioblastoma, traumatic brain injury, and Parkinson's disease when exogenously delivered, making it an attractive target for the treatment of glioblastoma. DAG may be of use as a tool to enhance delivery of therapeutics and imaging agents to sites of brain diseases.

Portion of EBV EBNA3A

Elastatinal is a natural product that has been shown to inhibit the protease activity of HIV-1. This inhibition may be due to its ability to bind to the cell surface and prevent the assembly of the virus-cell complex. Elastatinal binds to hydroxyl groups on proteins, which may inhibit enzymes in cells by preventing them from carrying out their functions. The biological sample can be any type of biological fluid or tissue, such as blood, saliva, semen, and vaginal secretions. Elastatinal is a natural product that has been shown to inhibit the protease activity of HIV-1. This inhibition may be due to its ability to bind to the cell surface and prevent the assembly of the virus-cell complex. Elastatinal binds to hydroxyl groups on proteins, which may inhibit enzymes in cells by preventing them from carrying out their functions. The biological sample can be any type of biological fluid or tissue, such as blood, saliva, semen, and

With the rise of multidrug-resistant bacteria like P. aeruginosa, the hunt for low toxicity inhibitors is paramount. A crucial part of their virulence/life cycle is cleavage of signal peptides. Type I signal peptides have a C-terminal hydrophilic domain containing a signal peptidase cleavage site commonly found in P. aeruginosa proteins that are cleaved by type I signal petidases (SPases). P. aeruginosa LasB, a type I signal peptide, is a crucial enzyme for bacterial invasion, it degrades elastin and thus aids tissue invasion, without cleavage by a SPase the protein is inactive. This peptide is an ideal candidate for enzymatic assay work in to SPase inhibitor investigations.Here we provide the substrate LasB sequence with the EDANS-Dabcyl donor quencher pair suitable for SPase inhibitor assays with FRET microscopy analysis. When this peptide is intact, fluorescence from the fluorophore (donor) EDAN is undetectable due to the proximity of the acceptor (quencher) Dabcyl. However, upon cleavage the fluorescence of the EDANS moiety, as measurably by excitation/emission 340/490nm, can be detected due to separation from the Dabcyl quencher.

The heptapeptide Alexamorelin is a member of the Growth Hormone secretagogues (GHS) family. These are synthetic molecules which act through the central nervous system to stimulate the secretion of somatotrophs, prolactin, adrenocorticotrophin and cortisol. Alexamorelin has also been shown to inhibit 125I-Tyr-Ala-HEX binding in tissues. Due to their stimulation of growth hormone release, they are known as non-approved pharmaceuticals and are a concern to sport's drug testing organisations.

Melittin is a 26-residue peptide originally isolated from venom of the European honeybee. Melittin is a cationic, hemolytic peptide from honey bee venom. Melittin lowers the surface tension at the plasma membrane and causes cell lysis. Melittin exhibits potent anti-inflammatory and antimicrobial activity. Melittin has been extensively used as a model peptide for observing membrane lipid-protein interactions.

TAT (48-60) amide 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 an uncharged C-terminal amide.

β-Amyloid 1-10 (Aβ1-10) 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.

Isotocin is a nonapeptide of the arginine vasopressin-oxytocin family produced exclusively in the preoptic area (POA) of teleosts. As a homologue of mammalian oxytocin, studying fish nonapeptides has shown that Isotocin mediates social and reproductive behaviour in fishes. Functional isotocin is stored in granules at the axon terminal with a carrier peptide, neurophysin. Stimuli leads to isotocin dissociation, to be released into the bloodstream or to cross over into the brain. It binds to G-protein coupled receptors (GPCRs), which subtype isotocin binds to defines the following physiological action. It, like other nonapeptides, is a neuromodulator in the CNS, but when distributed by the bloodstream, it acts as a peripheral hormone, such as regulating osmoregulation. Isotocin levels are sex-dependent and linked to the reproductive cycle.HPLC is a sensitive method to detect bioavailable isotocin and other nonapeptides. Measurement of mRNA levels of isotocin has been important to demonstrate the cyclical changes to regulate the endocrine calendar and diurnal rhythm. The level of isotocin is also considered a biomarker for aggression in behavioural indicators of fish welfare studies.

Galanin is a neuropeptide synthesised and released by the brainstem locus coeruleus (LC). Galanin is expressed in most LC neurons in rodents and humans. Galanin has been shown to inhibit LC activity by hyperpolarising LC neurons, suppressing their spontaneous firing rate, and enhancing alpha2-adrenergic receptor-mediated negative feedback. Galanin is also a potent trophic and neuroprotective factor throughout the nervous system.Galanin is widely distributed in the central nervous, peripheral, and endocrine systems. Galanin's overarching function is as an inhibitory, hyper-polarizing neuromodulator for classical neurotransmitters like acetylcholine and serotonin. Galanin interacts with 3 receptor subtypes, GalR1-3, these G protein-coupled receptors are inserted into the plasma membrane. GalR1 is believed to activate a Gβγ pathway to regulate MAPK activation. GalR2 can also activate the MAPK pathway, but unlike GalR1, there is detectable inositol phosphate production. GalR3 is associated with the Galphai/o pathway. Activation of the receptor leads to a cellular influx of K+. Each receptor has been associated with neurological diseases such as GalR3 with epilepsy.N-terminal fragments naturally occur in vivo, but their relevance is unclear. Some N-terminal fragments reduce metabolic and functional disorders in experimental heart damage. Using N-terminal fragments such as galanin (3-13) can clarify the function of full-length galanin during myocardial ischemia and reperfusion injury. This may highlight new agonists/antagonists for the galanin GalR receptors that can be putative therapeutic targets.