N-Formyl-Met-Leu-Phe-Lys (fMLFK) is a peptide, acts as a potent and selective agonist of FPR1, with EC₅₀s of 3.5 nM, 6.7 μM and 0.88 μM for FPR1, FPR2 and FPR2-D281^7.32G, respectively^[1].

EC50: 3.5 nM (FPR1), 6.7 μM (FPR2), 0.88 μM (FPR2-D281^7.32G)^[1]

565.73

C₂₇H₄₃N₅O₆S

67247-11-4

Formyl-Met-Leu-Phe-Lys

Formyl-MLFK

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

H₂O

Peptide Solubility and Storage Guidelines:

1.;;Calculate the length of the peptide.

2.;;Calculate the overall charge of the entire peptide according to the following table:

3.;;Recommended solution:

• [1]. He HQ, et al. Structural determinants for the interaction of formyl peptide receptor 2 with peptide ligands. J Biol Chem. 2014 Jan 24;289(4):2295-306.

N-Formyl-Met-Leu-Phe (fMLP; N-Formyl-MLF) is a chemotactic peptide and a specific ligand of N-formyl peptide receptor (FPR). N-Formyl-Met-Leu-Ph is reported to inhibit TNF-alpha secretion.

TNF-alpha^[1]

Binding of N-Formyl-Met-Leu-Phe to its specific cell surface receptor, N-formyl peptide receptor (FPR), triggers different cascades of biochemical events, eventually leading to cellular activation. FPR is a chemoattractant receptor belonging to the G protein-coupled receptor family. N-Formyl-Met-Leu-Phe promotes osteoblastic commitment and suppresses adipogenic commitment under osteoblastic differentiation conditions. N-Formyl-Met-Leu-Phe stimulates osteogenesis is associated with increased expression of osteogenic markers and mineralization. N-Formyl-Met-Leu-Phe inhibits expression of peroxisome proliferator-activated receptor-γ1. N-Formyl-Met-Leu-Phe-stimulated osteogenic differentiation is mediated via FPR1-phospholipase C/phospholipase D-Ca²⁺-calmodulin-dependent kinase II-ERK-CREB signaling pathways^[1]. N-Formyl-Met-Leu-Phe, a bacterial-derived peptide, induced proinflammatory cytokine gene expression in human peripheral blood monocytes. Bacterial products LPS and N-Formyl-Met-Leu-Phe synergistically induce inflammatory response via multiple signaling pathways. TLR4, IKKβ-IκBα, and NF-κB signaling pathways are involved in the synergistic induction of TNF-α via p65 nuclear translocation-dependent mechanisms^[2].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

N-Formyl-Met-Leu-Phe promotes bone formation in zebrafish and rabbits. Extensive skeletal development is evident at 5 dpf in over 80% of N-Formyl-Met-Leu-Phe-treated zebrafish. Treatment with N-Formyl-Met-Leu-Phe results in increased expression of Runx2. Bone marrow spaces are widely formed, and connective tissue covering bone is dense, like periosteum, in N-Formyl-Met-Leu-Phe-treated calvaria^[1]. N-Formyl-Met-Leu-Phe mediate release of calprotectin from PMN in vitro. It induces release of calprotectin from PMN in a dose dependent manner. A minimum of 10% of total PMN calprotectin is retained at concentrations of 0.1-10.0 nM of N-Formyl-Met-Leu-Phe^[3].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

437.55

C₂₁H₃₁N₃O₅S

59880-97-6

Formyl-Met-Leu-Phe

Formyl-MLF

Room temperature in continental US; may vary elsewhere.

DMSO : ≥ 82.5 mg/mL (188.55 mM)

H₂O : < 0.1 mg/mL (ultrasonic) (insoluble)

* “≥” means soluble, but saturation unknown.

请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 6 months; -20°C, 1 month。-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。

请根据您的实验动物和给药方式选择适当的溶解方案。以下溶解方案都请先按照 In Vitro 方式配制澄清的储备液，再依次添加助溶剂：

——为保证实验结果的可靠性，澄清的储备液可以根据储存条件，适当保存；体内实验的工作液，建议您现用现配，当天使用； 以下溶剂前显示的百
分比是指该溶剂在您配制终溶液中的体积占比；如在配制过程中出现沉淀、析出现象，可以通过加热和/或超声的方式助溶

• 1.

  请依序添加每种溶剂：;10% DMSO ;; 40% PEG300 ;; 5% Tween-80 ;; 45% saline

  Solubility: ≥ 2.08 mg/mL (4.75 mM); Clear solution

  此方案可获得 ≥ 2.08 mg/mL (4.75 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 20.8 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；向上述体系中加入50 μL Tween-80，混合均匀；然后继续加入 450 μL生理盐水定容至 1 mL。

  将 0.9 g 氯化钠，完全溶解于 100 mL ddH₂O 中，得到澄清透明的生理盐水溶液

• 2.

  请依序添加每种溶剂：;10% DMSO ;; 90% corn oil

  Solubility: ≥ 2.08 mg/mL (4.75 mM); Clear solution

  此方案可获得 ≥ 2.08 mg/mL (4.75 mM，饱和度未知) 的澄清溶液，此方案不适用于实验周期在半个月以上的实验。

  以 1 mL 工作液为例，取 100 μL 20.8 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Shin MK, et al. N-formyl-methionyl-leucyl-phenylalanine (fMLP) promotes osteoblast differentiation via the N-formyl peptide receptor 1-mediated signaling pathway in human mesenchymal stem cells from bone marrow. J Biol Chem. 2011 May 13;286(19):17133-43.

  [2]. Chen LY, et al. Synergistic induction of inflammation by bacterial products lipopolysaccharide and fMLP: an important microbial pathogenic mechanism. J Immunol. 2009 Feb 15;182(4):2518-24.

  [3]. Hetland G, et al. Chemotaxins C5a and fMLP induce release of calprotectin (leucocyte L1 protein) from polymorphonuclear cells in vitro. Mol Pathol. 1998 Jun;51(3):143-8.

Cells are cotransfected with either a dominant negative form of IκBα or a dominant negative form of IKKβ together with the NF-κB-dependent luciferase reporter plasmid. The plasmid pCMVβ is used as a control for transfection efficiency and this is monitored via the expression of β-galactosidase. Cells are transiently transfected with plasmids using DEAE-dextran. The transfected cells are cultivated for 48 h before a 6-h incubation in medium ±N-Formyl-Met-Leu-Phe, LPS, or N-Formyl-Met-Leu-Phe/LPS. Luciferase activity is determined by using the luciferase assay kit and a Monolight 3010 luminometer^[2].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Mice: N-Formyl-Met-Leu-Phe is prepared in sterile PBS. Under the anesthesia, mice are intranasally treated with LPS (0.3 mg/kg) or N-Formyl-Met-Leu-Phe (0.5 mg/kg) or N-Formyl-Met-Leu-Phe and LPS in 50 μL of sterile PBS (control), BAL is performed by cannulating the trachea with sterilized PBS, and cells from BAL fluid are stained with Wright-Giemsa stain after cytocentrifuge. For TNF-α protein release, BAL fluid is collected and secreted TNF-α is measured by ELISA as described above^[2].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Shin MK, et al. N-formyl-methionyl-leucyl-phenylalanine (fMLP) promotes osteoblast differentiation via the N-formyl peptide receptor 1-mediated signaling pathway in human mesenchymal stem cells from bone marrow. J Biol Chem. 2011 May 13;286(19):17133-43.

  [2]. Chen LY, et al. Synergistic induction of inflammation by bacterial products lipopolysaccharide and fMLP: an important microbial pathogenic mechanism. J Immunol. 2009 Feb 15;182(4):2518-24.

  [3]. Hetland G, et al. Chemotaxins C5a and fMLP induce release of calprotectin (leucocyte L1 protein) from polymorphonuclear cells in vitro. Mol Pathol. 1998 Jun;51(3):143-8.