a-2-binding peptide

A2-Binding peptide has involved in the assembly of MHC Class I molecules.

ATN-161 is an integrin α5β1 binding peptide and antagonist that inhibits VEGF-induced hCECs migration and angiogenesis. ATN-161 also suppresses spike protein interaction with integrin α5β1 and may be employed against SARS-CoV-2 infection.

MK-3207 is a highly potent and orally bioavailable small molecule antagonist of the calcitonin gene-related peptide (CGRP) receptor, demonstrating an in vitro IC50 of 0.12 nM and a Ki of 0.024 nM for the human receptor with exceptional selectivity over the related human AM1, AM2, CTR, and AMY3 receptors, though it exhibits lower affinity for CGRP receptors from other species such as canine and rodent; in vitro studies confirm its potent antagonism of human and rhesus monkey CGRP receptors (K(i) = 0.024 nM), and in vivo models show it produces a concentration-dependent inhibition of dermal vasodilation, requiring plasma concentrations of 0.8 nM and 7 nM to block 50% and 90% of the blood flow increase, respectively.

PKA inhibitor fragment (6-22) amide Acetate is a synthetic peptide which selectively inhibits PKA activity by binding to its substrate site (IC50 < 2 nM).

YM44781 is a non-peptide tachykinin receptor antagonist. YM44781 exhibits high binding affinities at NK(1) (pK(i) = 9.09 +/- 0.02) and NK(2) (pK(i) = 9.94 +/- 0.03) receptors, respectively.

Tat-NR2BAA is an inactive control peptide of Tat-NR2B9c. It shares a similar sequence with Tat-NR2B9c, but possesses a double-point mutation in the COOH terminal tSXV motif. This mutation renders Tat-NR2BAA unable to bind PSD-95. Tat-NR2B9c, on the other hand, is a membrane-permeable peptide that interferes with PSD-95/NMDAR binding. This interference leads to the decoupling of NR2B- and/or NR2A-type NMDARs from PSD-95[1][2].

PAR2 (1-6) amide is a synthetic peptide agonist of proteinase-activated receptor 2 (PAR2) that corresponds to residues 1-6 of the amino terminal tethered ligand sequence of human PAR2 and residues 37-42 of the full-length sequence.1It binds to NCTC 2544 cells expressing human PAR2 (Ki= 9.64 μM in a radioligand binding assay) and induces calcium mobilization in the same cells (EC50= 0.075 μM).2PAR2 (1-6) amide (100 μM) reduces colony formation of A549 lung cancer cells.1It induces superoxide production and degranulation in isolated human eosinophils when used at a concentration of 500 μM.3PAR2 (1-6) amide (5 μmol/kg) induces tear secretion in rats when used in combination with amastatin .4 1.Bohm, S.K., Kong, W., Bromme, D., et al.Molecular cloning, expression and potential functions of the human proteinase-activated receptor-2Biochem. J.314(Pt 3)1009-1016(1996) 2.Kanke, T., Ishiwata, H., Kabeya, M., et al.Binding of a highly potent protease-activated receptor-2 (PAR2) activating peptide, [3H]2-furoyl-LIGRL-NH2, to human PAR2Br. J. Pharmacol.145(2)255-263(2005) 3.Miike, S., McWilliam, A.S., and Kita, H.Trypsin induces activation and inflammatory mediator release from human eosinophils through protease-activated receptor-2J. Immunol.167(11)6615-6622(2001) 4.Nishikawa, H., Kawai, K., Tanaka, M., et al.Protease-activated receptor-2 (PAR-2)-related peptides induce tear secretion in rats: Involvement of PAR-2 and non-PAR-2 mechanismsJ. Pharmacol. Exp. Ther.312(2)324-331(2005)

Nebentan (YM598) is a potent, selective and orally active non-peptide endothelin ETA receptor antagonist through the modification of Bosentan . Nebentan inhibits [125I] endothelin-1 binding to cloned human endothelin ETA and ETB receptor, with Ki of 0.697 nM and 569 nM, respectively[1]. YM598 can ameliorate the progression of cor pulmonale and myocardial infarction in vivo[2]. Nebentan inhibits the specific binding of [125I] endothelin-1 to endothelin ETA and ETB receptors in a concentration dependent manner,Ki values are 0.697 nM and 1.53 nM for human and rat endothelin ETA receptors, respectively. In contrast, YM598 exhibits low affinities for human and rat endothelin ETB receptors, with Ki values of 569 nM and 155 nM,respectively[1].In measurement of intracellular Ca2+ concentration, Nebentan concentration-dependently inhibits the increase in [Ca2+]i induced by 10 nM endothelin-1 in both CHO cells and A10 cells, the IC50 values are 26.2 nM for CHO cells and 26.7 nM for A10 cells, respectively[1]. Nebentan (oral administration; 0.1-1 mg/kg; 4 weeks) significantly inhibits the progression of pulmonary hypertension and the development of right ventricular hypertrophy[2].Nebentan (oral administration; 1 mg/kg; 30 weeks) significantly ameliorates the poor survival rate of CHF rats, it markedly reduces the hypertrophy of both ventricles as well as pulmonary congestion[2]. [1]. Hironori Yuyama, et al. Pharmacological Characterization of YM598, an Orally Active and Highly Potent Selective Endothelin ET(A) Receptor Antagonist. Eur J Pharmacol. 2003 Sep 30;478(1):61-71. [2]. Akira Fujimori, et al. YM598, an Orally Active ET(A) Receptor Antagonist, Ameliorates the Progression of Cardiopulmonary Changes and Both-Side Heart Failure in Rats With Cor Pulmonale and Myocardial Infarction. J Cardiovasc Pharmacol. 2004 Nov;44 Suppl 1:S354-7.

PKI PKA Inhibitor (5-24) is a synthetic peptide inhibitor of PKA (cAMP-dependent protein kinase) (Ki= 2.3 nM) derived from the active site of the skeletal muscle inhibitor protein.1It mimics the protein substrate by binding to the catalytic site through the arginine-cluster basic subsite.1The prominent enzyme-substrate interaction site occurs where PKA catalytic subunit residues Tyr235and Phe239form a sandwich-like structure with residue Phe10of PKI (5-24).2

RWJ-56110 dihydrochloride is a potent, selective, peptide-mimetic inhibitor of PAR-1 activation and internalization (binding IC50=0.44 μM), showing no effect on PAR-2, PAR-3, or PAR-4. It inhibits the aggregation of human platelets induced by SFLLRN-NH2 (IC50=0.16 μM) and thrombin (IC50=0.34 μM), with high selectivity relative to U46619. RWJ-56110 dihydrochloride also blocks angiogenesis and the formation of new vessels in vivo, and induces cell apoptosis[1][2].

Deltorphin II is a peptide agonist of δ2-opioid receptors.1,2It is selective for δ-opioid receptors over μ- and κ-opioid receptors in radioligand bindings assays (Kis = 0.0033, >1, and >1 μM, respectively) and induces [35S]GTPγS binding in mouse brain membrane preparations (EC50= 0.034 μM). Deltorphin II (0.12 mg/kg) decreases the infarction zone:risk zone ratio in a rat model of myocardial ischemia-reperfusion injury induced by coronary occlusion, an effect that can be reversed by the δ2-opioid receptor antagonist naltriben but not the δ1-opioid receptor antagonist BNTX.3Intrathecal administration of deltorphin II (15 μg/animal) increases latency to withdraw in the paw pressure and tail-flick tests in rats.4 1.Raynor, K., Kong, H., Chen, Y., et al.Pharmacological characterization of the cloned κ-, δ-, and μ-opioid receptorsMol. Pharm.45(2)330-334(1994) 2.Scherrer, G., Befort, K., Contet, C., et al.The delta agonists DPDPE and deltorphin II recruit predominantly mu receptors to produce thermal analgesia: A parallel study of mu, delta and combinatorial opioid receptor knockout miceEur. J. Neurosci.19(8)2239-2248(2004) 3.Maslov, L.N., Barzakh, E.I., Krylatov, A.V., et al.Opioid peptide deltorphin II simulates the cardioprotective effect of ischemic preconditioning: role of δ2-opioid receptors, protein kinase C, and KATP channelsBull. Exp. Biol. Med.149(5)591-593(2010) 4.Labuz, D., Toth, G., Machelska, H., et al.Antinociceptive effects of isoleucine derivatives of deltorphin I and deltorphin II in rat spinal cord: A search for selectivity of delta receptor subtypesNeuropeptides32(6)511-517(1998)

Calcitonin is a peptide hormone that lowers blood calcium level and inhibits bone resorption. It belongs to the calcitonin family of peptides, which also includes amylin , calcitonin gene-related peptide , and adrenomedullin. The binding of salmon calcitonin to the human calcitonin receptor (CTR) is not modulated by receptor activity-modifying proteins (RAMPs), which influence affinity of human calcitonin to CTR. Salmon calcitonin binds to human CTR2 with IC50 values of 0.933, 0.224, 0.134, and 0.317 nM alone and with RAMP1, 2, or 3, respectively. It induces cAMP accumulation in COS-7 cells transfected with CTR2 (EC50 = 0.166 nM). Salmon calcitonin inhibits bone resorption by osteoclasts in a pit formation assay using rat bone slices (ID50 = 0.003 pg/mL) and lowers calcium level in vivo in a bioassay of hypocalcemia in rats (ED15 = 33.9 mg/kg). Formulations containing salmon calcitonin have been used to treat hypercalcemia, bone destruction by osteoporosis, and Paget's disease.

Son of sevenless homolog 1 (Sos1) is a guanine nucleotide exchange factor (GEF) that directs the exchange of Ras-GDP to Ras-GTP by binding to SH3 domains of the growth factor receptor-bound protein 2 (Grb2), leading to the activation of ERK. Ras inhibitory peptide is a synthetic peptide that contains the sequence PVPPR, which corresponds to a region within human Sos1 that interacts with an SH3 domain of Grb2. It specifically blocks the interaction of the GEF with Grb2, preventing an interaction that is essential for Ras activation by receptor tyrosine kinases, including epidermal growth factor receptor.

BMSpep-57, a potent macrocyclic peptide inhibitor, competitively disrupts the PD-1/PD-L1 interaction, demonstrating a significant inhibitory concentration (IC50) of 7.68 nM. It exhibits binding affinity towards PD-L1 with dissociation constants (Kd) of 19 nM and 19.88 nM in MicroScale Thermophoresis (MST) and Surface Plasmon Resonance (SPR) assays, respectively. This compound enhances T cell functionality by promoting Interleukin-2 (IL-2) production within Peripheral Blood Mononuclear Cells (PBMCs).

Tyrosinase-related Protein 2 (TRP-2) (181-188) is a peptide derived from TRP-2, specifically corresponding to residues 180-188, and it is the primary epitope within TRP-2 recognized by anti-B16 CTLs. Additionally, it conforms to the binding motif of the MHC class I H2-Kb.

DS45500853 is a novel ERRα agonist that does not activate PPARγ and promotes the recruitment of PGC-1α coactivating peptide by directly binding to ERRα. It has potential for the treatment of metabolic disorders such as type 2 diabetes.

Phytochelatin 2, a short plant peptide, serves as an essential metal-binding compound. Phytochelatins are a diverse group of plant compounds that play a crucial role in chelating metals, safeguarding against metal toxicity, and maintaining metal homeostasis.

NBI-42902 is a potent inhibitor of peptide radioligand binding to the human GnRH receptor (K(i) = 0.56 nm). Tritiated NBI-42902 binds with high affinity (K(d) = 0.19 nm) to a single class of binding sites and can be displaced by a range of peptide and nonpeptide GnRH receptor ligands. In vitro experiments demonstrate that NBI-42902 is a potent functional, competitive antagonist of GnRH stimulated IP accumulation, Ca(2+) flux, and ERK1/2 activation. It did not stimulate histamine release from rat peritoneal mast cells. Finally, it is effective in lowering serum LH in castrated male macaques after oral administration. Overall, these data provide a benchmark of pharmacological characteristics required for a nonpeptide GnRH antagonist to effectively suppress gonadotropins in humans and suggest that NBI-42902 may have clinical utility as an oral agent for suppression of the hypothalamic-pituitary-gonadal axis. (source: Endocrinology. 2007 Feb;148(2):857-67. Epub 2006 Nov 9.)

Bivalirudin TFA, a synthetic 20-residue peptide, serves as a reversible inhibitor of thrombin. Its IC50 value highlights its target specificity in vitro, where, combined with Eptifibatide (8 mg/mL) at a low concentration (70 ng/mL), it significantly reduces platelet aggregation induced by thrombin (0.2 U/mL) by approximately 90% [1]. The compound demonstrates no effect on thrombin generation assay (TGA) parameters up to 10 μmol/L [2]. Additionally, it facilitates the binding of MPO to BAEC, leading to functional alterations such as increased NO consumption and enhanced MPO-mediated redox modifications [3]. In vivo studies reveal its efficacy in preventing the rise of antiheparin/PF4 antibody IgG levels in rats, with significant findings from the toxicokinetic assessment signaling its safety profile at tested doses, although higher doses resulted in fatalities [4][5]. In clinical trials, its antithrombotic effects were explored, comparing it with alternatives like Ticagrelor and Clopidogrel in a Phase 4 study.

Nonapeptide-1 (Melanostatine-5) acetate salt is a peptide hormone that functions as a selective and competitive antagonist of the melanocortin 1 receptor (MC1R) with a binding affinity (K i) of 40 nM. It effectively inhibits α-MSH-induced increases in intracellular cyclic AMP (cAMP) and melanosome dispersion in melanocytes, with inhibitory concentrations (IC 50) of 2.5 nM and 11 nM, respectively. By inhibiting melanin synthesis, Nonapeptide-1 acetate salt is used in research related to skin pigmentation, adrenal gland steroid production regulation, and skin cancer [1] [2] [3].

GRGDSPK TFA (EMD 56574 TFA) is a peptide containing the Arg-Gly-Asp (RGD) sequence, serving as a competitive and reversible inhibitor of integrin-fibronectin binding. This compound is utilized in research to elucidate integrins' involvement in bone formation and resorption [1] [2].

COG 133 TFA is a fragment of Apolipoprotein E (APOE) peptide. COG 133 TFA competes with the ApoE holoprotein for binding the LDL receptor, with potent anti-inflammatory and neuroprotective effects. COG 133 TFA is also a nAChR antagonist with an IC 50 of 445 nM [1] [2] .

M1145 TFA, a chimeric peptide, acts as a selective agonist for the galanin receptor type 2 (GAL2), demonstrating a binding affinity (K i) of 6.55 nM. It exhibits significantly greater selectivity for GAL2, with over 90-fold and 76-fold higher affinity compared to GAL1 (K i = 587 nM) and GalR3 (K i = 497 nM), respectively. Additionally, M1145 TFA enhances galanin signal transduction mechanisms [1].

Cyclotraxin B TFA, a cyclic peptide, is a highly potent and selective non-competitive inhibitor of TrkB, effectively impeding BDNF-triggered TrkB activity without altering BDNF binding affinity, with an IC50 of 0.30 nM. It crosses the blood-brain barrier, demonstrating analgesic and anxiolytic-like behavioral effects [1] [2] [3].