pt 100

Talabostat mesylate (PT100) 是一种具有口服活性和非选择性的二肽基肽酶 IV 抑制剂(IC50< 4 nM;Ki= 0.18 nM)。Talabostat mesylate 是成纤维细胞活化蛋白的第一个临床抑制剂(IC50= 560 nM)，抑制 DPP8 9 (IC50= 4 11 nM;Ki= 1.5 0.76 nM)，静息细胞脯氨酸二肽酶(IC50= 310 nM)、DPP2 和一些其他 DASH 家族酶。Talabostat mesylate 具有抗肿瘤和造血刺激活性 。

Talabostat (PT100, Val-boroPro) is a potent, nonselective and orally available dipeptidyl peptidase IV (DPP-IV) inhibitor with a Ki of 0.18 nM. Talabostat is a nonselective DPP-IV inhibitor, inhibiting DPP8 9, FAP, DPP2 and some other DASH family enzymes essentially as potently as it inhibits DPP-IV[1]. Talabostat stimulates the immune system by triggering a proinflammatory form of cell death in monocytes and macrophages known as pyroptosis. The inhibition of two serine proteases, DPP8 and DPP9, activates the proprotein form of caspase-1 independent of the inflammasome adaptor ASC[2]. Talabostat competitively inhibits the dipeptidyl peptidase (DPP) activity of FAP and CD26 DPP-IV, and there is a high-affinity interaction with the catalytic site due to the formation of a complex between Ser630 624 and the boron of talabostat[3]. Talabostat can stimulate immune responses against tumors involving both the innate and adaptive branches of the immune system. In WEHI 164 fibrosarcoma and EL4 and A20 2J lymphoma models, PT-100 causes regression and rejection of tumors. The antitumor effect appears to involve tumor-specific CTL and protective immunological memory. Talabostat treatment of WEHI 164-inoculated mice increases mRNA expression of cytokines and chemokines known to promote T-cell priming and chemoattraction of T cells and innate effector cells[3]. Talabostat treated mice show significant less fibrosis and FAP expression is reduced. Upon PT100 treatment, significant differences in the MMP-12, MIP-1α, and MCP-3 mRNA expression levels in the lungs are also observed. Treatment with PT100 in this murine model of pulmonary fibrosis has an anti-fibro-proliferative effect and increases macrophage activation[4]. [1]. Connolly BA, et al. Dipeptide boronic acid inhibitors of dipeptidyl peptidase IV: determinants of potencyand in vivo efficacy and safety. J Med Chem. 2008 Oct 9;51(19):6005-13. [2]. Okondo MC, et al. DPP8 and DPP9 inhibition induces pro-caspase-1-dependent monocyte and macrophage pyroptosis. Nat Chem Biol. 2017 Jan;13(1):46-53. [3]. Adams S, et al. PT-100, a small molecule dipeptidyl peptidase inhibitor, has potent antitumor effects and augments antibody-mediated cytotoxicity via a novel immune mechanism. Cancer Res. 2004 Aug 1;64(15):5471-80. [4]. Egger C, et al. Effects of the fibroblast activation protein inhibitor, PT100, in a murine model of pulmonary fibrosis. Eur J Pharmacol. 2017 Aug 15;809:64-72.

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)

Guanosine 5’-diphosphate (GDP) is a purine nucleotide and biosynthetic precursor of guanosine 5’-triphosphate .1It has been used to study the conformations of GTPases.2GDP (100 μM) activates sulfonylurea receptor 2B (SUR2B) linked to the inward-rectifier potassium channel 6.1 (Kir6.1) in HEK293T cells in a patch-clamp assay.3 1.Berg, J.M., Tymoczko, J.L., and Stryer, L.Biochemistry(2002) 2.Vetter, I.R., and Wittinghofer, A.The guanine nucleotide-binding switch in three dimensionsScience294(5545)1299-1304(2001) 3.Yamada, M., Isomoto, S., Matsumoto, S., et al.Sulphonylurea receptor 2B and Kir6.1 form a sulphonylurea-sensitive but ATP-insensitive K+ channelJ. Physiol.499(Pt 3)715-720(1997)

Palmitoylcholine is an acyl choline.1It inhibits protein kinase C activity when used at a concentration of 100 μM.2Palmitoylcholine induces hemolysis in rat erythrocytes.3Plasma levels of palmitoylcholine are decreased in female patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).1 1.Germain, A., Barupal, D.K., Levine, S.M., et al.Comprehensive circulatory metabolomics in ME/CFS reveals disrupted metabolism of acyl lipids and steroidsMetabolites10(1)34(2020) 2.Nakadate, T., and Blumberg, P.M.Modulation by palmitoylcarnitine of protein kinase C activationCancer Res.47(24 Pt 1)6537-6542(1987) 3.Cho, K.S., and Proulx, P.Interactions of acyl carnitines and other lysins with erythrocytes and reconstituted erythrocyte lipoproteinsBiochim. Biophys. Acta318(1)50-60(1973)