serum

Human Serum Albumin (HSA) is the most abundant protein in human plasma, is produced in the liver and is water soluble, with a molecular weight of 66.5 kDa. HSA inhibits Alzheimer's disease by selectively binding to cross-structured A oligomers. HSA is a key endogenous inhibitor of amyloid-β (Αβ) aggregation. HSA is used as a carrier protein in cell culture for the transport of fatty acids, steroids, and thyroid hormones and to regulate osmolality of the blood, and is also used in drug delivery studies, immunoassays, and cell freezing. cell freezing.

Anserine (L-Anserine) is a dipeptide containing β-alanine and histidine, which can be found in the skeletal muscle and brain of mammals and birds. Anserine is not cleaved by serum carnosinase and act as biochemical buffers, chelators, antioxidants, and anti-glycation agents. Anserine improves memory functions in Alzheimer's disease (AD)-model mice.

Bradykinin (acetate) is an active peptide that is generated by the kallikrein-kinin system. It is a inflammatory mediator and also recognized as a neuromediator and regulator of several vascular and renal functions. Enzymatically produced from kallidin in the blood, it is a powerful vasodilator that causes smooth muscle contraction, and may mediate inflammation. It has a role as a human blood serum metabolite and a vasodilator agent. It is a tautomer of a bradykinin(2+).

Angiotensin 1 2 (5-7) acetate is a peptide with the sequence H2N-Ile-His-Pro-OH. Angiotensin is an oligopeptide and is a hormone and a powerful dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. It

Kisspeptin-54 is a peptide ligand of the orphan G protein-coupled receptor GPR54 (Kis = 1.81 and 1.45 nM for rat and human receptors, respectively).1 It is a 54 amino acid peptide encoded by the metastasis suppressor gene KISS-1. Kisspeptin-54 induces calcium mobilization in CHO-K1 cells expressing rat and human receptors (EC50s = 1.39 and 5.47 nM, respectively). It also induces arachidonic acid release in CHO cells expressing rat and human GPR54 in a concentration-dependent manner. Kisspeptin-54 (10-1,000 nM) inhibits insulin secretion from isolated mouse pancreatic β-cells in the presence of 2.8 mM, but not 11.1 mM, glucose.2 Kisspeptin-54 (1-5 nmol, i.c.v.) increases serum levels of luteinizing hormone (LH) and follicular stimulating hormone (FSH) in mice, an effect which is reversed by the gonadotropin releasing hormone (GNRH) antagonist acycline.3References1. Kotani, M., Detheux, M., Vandenbogaerde, A.L., et al. The metastasis suppressor gene KiSS-1 encodes kisspeptins, the natural ligands of the orphan G protein-coupled receptor GPR54. J. Biol. Chem. 276(37), 34631-34636 (2001).2. Vikman, J., and Ahrén, B. Inhibitory effect of kisspeptins on insulin secretion from isolated mouse islets. Diabetes Obes. Metab. 11(Suppl 4), 197-201 (2009).3. Gottsch, M.L., Cunningham, M.J., Smith, J.T., et al. A role for kisspeptins in the regulation of gonadotropin secretion in the mouse. Endocrinology 145(9), 4073-4077 (2004). Kisspeptin-54 is a peptide ligand of the orphan G protein-coupled receptor GPR54 (Kis = 1.81 and 1.45 nM for rat and human receptors, respectively).1 It is a 54 amino acid peptide encoded by the metastasis suppressor gene KISS-1. Kisspeptin-54 induces calcium mobilization in CHO-K1 cells expressing rat and human receptors (EC50s = 1.39 and 5.47 nM, respectively). It also induces arachidonic acid release in CHO cells expressing rat and human GPR54 in a concentration-dependent manner. Kisspeptin-54 (10-1,000 nM) inhibits insulin secretion from isolated mouse pancreatic β-cells in the presence of 2.8 mM, but not 11.1 mM, glucose.2 Kisspeptin-54 (1-5 nmol, i.c.v.) increases serum levels of luteinizing hormone (LH) and follicular stimulating hormone (FSH) in mice, an effect which is reversed by the gonadotropin releasing hormone (GNRH) antagonist acycline.3 References1. Kotani, M., Detheux, M., Vandenbogaerde, A.L., et al. The metastasis suppressor gene KiSS-1 encodes kisspeptins, the natural ligands of the orphan G protein-coupled receptor GPR54. J. Biol. Chem. 276(37), 34631-34636 (2001).2. Vikman, J., and Ahrén, B. Inhibitory effect of kisspeptins on insulin secretion from isolated mouse islets. Diabetes Obes. Metab. 11(Suppl 4), 197-201 (2009).3. Gottsch, M.L., Cunningham, M.J., Smith, J.T., et al. A role for kisspeptins in the regulation of gonadotropin secretion in the mouse. Endocrinology 145(9), 4073-4077 (2004).

Acyline is a novel GnRH antagonist found in animal studies to be a potent suppressor of circulating gonadotropin and testosterone (T) levels. Acyline inhibits basal and GnRH-stimulated serum testosterone concentrations in male dogs. Acyline prevented ovulation, but did not affect ovarian follicular development or gestational corpora lutea in the domestic cat. A single dose of the potent gonadotropin-releasing hormone antagonist acyline suppresses gonadotropins and testosterone for 2 weeks in healthy young men.

Pemvidutide, a dual GLP-1R GCGR agonist, significantly lowers body weight, liver fat, and serum lipids, holding promise for non-alcoholic steatohepatitis (NASH) and obesity research [1].

β-Amyloid 22-35 (Amyloid β-Protein 22-35) TFA, a fragment comprising residues 22-35 of the β-amyloid protein, exhibits cytotoxicity towards cultured rat hippocampal neurons in serum-free media. It aggregates and forms typical amyloid fibrils in neutral buffer solution, mirroring those observed with the full-length β-amyloid protein [1].

Enterostatin (rat), a procolipase activation peptide with oral activity, selectively diminishes fat consumption and lowers serum cholesterol through a CCK1 receptor-dependent mechanism [1] [2].

PTH (2-38) (human) plays a role in bone anabolism and can elevate serum levels of INS-PTH (complete N-terminal specific PTH) [1].

Lys-Phe-Glu-Arg-Gln promotes cytosolic protein degradation in serum-deprived human diploid fibroblasts [1].

Kisspeptin-10, a neuropeptide present in the brains, ovaries, and testes of zebrafish, plays a critical role in gonadal development and steroid expression. At a concentration of 10 ng/ml, it enhances the mRNA levels for the luteinizing hormone (Lh) receptor and both progestin receptor a (Pra) and Prb in zebrafish ovarian follicles. In female goldfish, doses of 0.1 and 1 µg/g of Kisspeptin-10 elevate serum levels of luteinizing hormone, with no similar effect observed in male goldfish.

F1, an anti-inflammatory peptide, incorporates the HIV-1 Tat protein transduction domain linked with a 15-amino acid sequence from residues 46-60 of the inhibitor of NF-κB kinase-interacting peptide (IKIP). It effectively blocks LPS-induced phosphorylation of IκB kinase α (IKKα) and IKKβ, along with the nuclear translocation of NF-κB (p65) in mouse peritoneal macrophages at 5 µM concentration. F1, administered at 5 mg/kg in vivo, significantly reduces IL-6, TNF-α, and IL-1β serum levels and enhances survival in a mouse sepsis model induced by LPS.

Gastric inhibitory peptide 1 (GIP-1) (3-42), a fragment of the incretin hormone GIP and antagonist to the GIP receptor, is generated through the action of serum dipeptidyl peptidase 4 (DDP-4). When administered at 25 nmol/kg to an ob/ob mouse diabetes model, GIP-1 (3-42) elevates plasma glucose levels and lowers plasma insulin levels, demonstrating its effect on reducing insulin secretion from BRIN-BD11 pancreatic cells at a concentration of 100 nM.

Pap12-6, an antibacterial peptide originating from the first twelve N-terminal amino acids of papiliocin found in P. xuthus larvae, exhibits activity against a range of eight Gram-negative bacteria (e.g., E. coli, P. aeruginosa, S. syphimurium with MIC50s=4-8 µM) and Gram-positive bacteria (e.g., S. aureus, methicillin-resistant S. aureus 3126, B. subtilis, and S. epidermidis with MIC50s=4-8 µM), without compromising the viability of human erythrocytes, mouse RAW 264.7 macrophages, human HaCaT keratinocytes, or human HEK293 kidney cells at 25 µM. It causes membrane depolarization in E. coli at 4 and 8 µM and, upon preincubation at 10 µM, decreases nitrite (NO2-), Tnf-α, and Il-6 secretion in LPS-stimulated RAW 264.7 macrophages. In a murine model, Pap12-6 enhances survival rates and diminishes colony forming units (CFUs) in several organs upon E. coli infection at 10 mg/kg and 1 mg/kg doses, respectively. Additionally, at a 1 mg/kg dose, it lowers serum aspartate aminotransferase (AST) and alanine transaminase (ALT) levels, as well as blood urea nitrogen levels in E. coli-induced sepsis, indicating its therapeutic potential for bacterial infections without affecting host cell viability.

EPI-X4, an endogenous peptide fragment of human serum albumin (amino acids 408-423), serves as an antagonist to the chemokine (C-X-C motif) receptor 4 (CXCR4). It effectively prevents calcium mobilization and receptor internalization triggered by chemokine (C-X-C motif) ligand 12 (CXCL12) in HEK293 cells with CXCR4 expression, at concentrations between 0.8 and 1,000 µM. Moreover, EPI-X4 hampers the CXCL12-driven migration of both Jurkat T cells and human CD34+ hematopoietic stem cells. In an acute allergic airway hypereosinophilia mouse model, EPI-X4 intrinsically decreases Cxcr4-dependent inflammatory cell infiltration in airways at a dose of 16 µmol/kg. Additionally, increased urinary EPI-X4 levels, inversely related to glomerular filtration rate (GFR), are observed in chronic kidney disease patients, indicating its potential biomarker role.

Klotho-derived peptide 1 (KP1) (56-87), a peptide originating from the human Klotho protein, disrupts TGF-β signaling by binding to TGF-β receptor types 1 and 2 (TGFBR1 and TGFBR2; Kds = 1.41 and 14.6 µM, respectively). Preincubation with KP1 at a concentration of 10 µg/ml hinders the TGF-β-induced escalation of fibronectin and α-smooth muscle actin (α-SMA) levels in NRK-49F rat fibroblasts. Furthermore, in vivo studies reveal that KP1, administered at 1 mg/kg per day, preferentially accumulates in damaged kidneys, leading to significant reductions in serum creatinine and blood urea nitrogen levels, indicators of improved kidney function. Additionally, it decreases kidney fibrosis in mouse models of unilateral ureteral obstruction (UUO) and unilateral ischemia-reperfusion injury-induced renal fibrosis.

1-Linoleoyl lysophosphatidic acid (1-linoleoyl LPA), a glycerophospholipid with linoleic acid at its sn-1 position, acts as an LPA2 receptor agonist and is the predominant LPA form in both mouse and human plasma. This compound preferentially boosts intracellular calcium in Sf9 cells expressing the LPA2 receptor (EC50 = ~10 nM), compared to those with LPA1 and LPA3 receptors (EC50s = ~200 and ~80 nM, respectively). Notably, 1-linoleoyl LPA serum concentrations are elevated in mice with NCTC clone 2472 tumors, while its plasma levels are reduced in primary progressive multiple sclerosis patients—unlike in those with relapsing-remitting multiple sclerosis—and inversely associate with the severity of neurological deficits.

Pep2 peptide, a peptide ligand for CD36 (transmembrane glycoprotein or scavenger receptor B2), exhibits selective binding to CD36 over human serum albumin (HSA), IgG, and CD44 in cell-free assays at 1 mM concentration. Pep2 peptide-functionalized micelles, when loaded with the anticancer agent doxorubicin, significantly enhance the cellular uptake and cytotoxicity of doxorubicin in HepG2 hepatocellular carcinoma cells that overexpress CD36, compared to micelles without Pep2 peptide.

HPN328 is a humanized trispecific T-cell activating construct (TriTAC) that targets CD3 to engage T cells, targets HSA to extend its half-life, and targets DLL3 on tumor cells. It effectively induces T-cell-mediated cytotoxicity against DLL3-expressing small cell lung cancer (SCLC), leading to tumor regression and sustained antitumor immunity. Molecular weight: 53.06 kDa.

CRP, an acute phase serum protein synthesized in response to inflammatory cytokines, produces antitumor effects in animals. The fragment CRP (174-185) (RS-83277) shows similar activity by significantly enhancing the tumoricidal activity of human monocytes

C-Reactive Protein (CRP) 174-185 acetate is an acute phase serum protein synthesized in response to inflammatory cytokines, produces antitumor effects in animals. The fragment CRP (174-185) (RS-83277) shows similar activity by significantly enhancing the

Osteogenic Growth Peptide (OGP) is a short, naturally occurring 14-mer growth factor peptide found in serum at μM concentrations and is a key factor in the systemic osteogenic response to local bone marrow injury.

Osteogenic Growth Peptide, OGP acetate is a short, naturally occurring 14-mer growth factor peptide found in serum at μM concentrations. Osteogenic growth peptide OGP is a key factor in the mechanism of the systemic osteogenic response to local bone marro