Recombinant Human Myeloperoxidase Protein, CF Summary
Ala49-Ser745, with a C-terminal 10-His tag
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.
|Formulation||Lyophilized from a 0.2 μm filtered solution in Tris and NaCl.|
|Reconstitution||Reconstitute at 0.5-1 mg/mL in sterile, deionized water.|
|Shipping||The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.|
|Stability & Storage:||Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
- Assay Buffer: 50 mM NaH2PO4, pH 7.0
- Recombinant Human Myeloperoxidase/MPO (rhMPO) (Catalog # 3174-MP)
- Hydrogen Peroxide Solution, 30% (v/v) (H2O2) (Sigma, Catalog # H1009)
- Guaiacol (Acros Organics, Catalog # AC120192500)
- Clear StripWell Microplate (Costar, Catalog # 92592)
- Plate Reader with Absorbance reading capability (Model: Spectramax Plus by Molecular Devices) or equivalent
- Prepare 100 mM guaiacol in Assay Buffer by shaking or stirring for 30 minutes at room temperature prior to use. Note: Protect guaiacol solution from light.
- Dilute rhMPO to 1 µg/mL in Assay Buffer.
- Dilute hydrogen peroxide from 30% to 0.00667% in Assay Buffer.
- Load in a clear microplate 20 µL of 1 µg/mL of rhMPO and 30 µL 0.00667% hydrogen peroxide, and start the reaction by adding 50 µL of 100 mM guaiacol.
- Read at 470 nm in kinetic mode for 5 minutes.
- Calculate specific activity:
Specific Activity (pmol/min/µg) =
|Adjusted Vmax* (OD/min) x Conversion Factor** (pmol/OD)|
|amount of enzyme (µg)|
*Adjusted for Substrate Blank
**Derived using known concentrations of hydrogen peroxide ranging from 20 to 300 µM. Each point contains 10 µg/mL of rhMPO (an amount so that the reaction will be completed in a short period of time) and 50 mM guaiacol. After each reaction is complete, the product is measured at 470 nm (read endpoint about every 20 seconds to find the maximum absorbance for each point). The maximum values of Abs470 (y-axis) and pmol of hydrogen peroxide (x axis) for each point is plotted linearly (y = mx + b) and the slope is calculated (m). The conversion factor is derived from the following equation as a unit of pmol/OD. It is multiplied by 2 because one mol of hydrogen peroxide is equal to two mol of oxidized guaicol (product).
Conversion Factor = (1/slope(m)) x 2 = pmol/OD
- rhMPO: 0.020 μg
- Hydrogen Peroxide: 0.002%
- Guaiacol: 50 mM
Myeloperoxidase (MPO) is a heme-containing enzyme belonging to the XPO subfamily of peroxidases. It is an abundant neutrophil and monocyte glycoprotein that catalyzes the hydrogen peroxide-dependent conversion of chloride, bromide, and iodide to multiple reactive species (1). Post-translational processing of MPO involves the insertion of a heme moiety and the proteolytic removal of both a propeptide and a 6 aa internal peptide (2). This results in a disulfide-linked dimer composed of a 60 kDa heavy and 12 kDa light chain that associate into a 150 kDa enzymatically active tetramer. The tetramer contains two heme groups and one disulfide bond between the heavy chains (2). Alternate splicing generates two additional isoforms of MPO, one with a 32 aa insertion in the light chain, and another with a deletion of the signal sequence and part of the propeptide (3). Human and mouse MPO share 87% aa sequence identity. MPO activity results in protein nitrosylation and the formation of 3-chlorotyrosine and dityrosine crosslinks (4‑6). Modification of ApoB100, as well as the lipid and cholesterol components of LDL and HDL, promotes the development of atherosclerosis (5, 7‑9). MPO is also associated with a variety of other diseases (1), and inhibits vasodilation in inflammation by depleting the levels of NO (10). Serum albumin functions as a carrier protein during MPO movement to the basolateral side of epithelial cells (11). MPO is stored in neutrophil azurophilic granules. Upon cellular activation, it is deposited into pathogen-containing phagosomes (2). While mice lacking MPO are impaired in clearing select microbial infections, MPO deficiency in humans does not necessarily result in heightened susceptibility to infections (12, 13).
- Klebanoff, S.J. (2005) J. Leukoc. Biol. 77:598.
- Hansson, M. et al. (2006) Arch. Biochem. Biophys. 445:214.
- Hashinaka, K. et al. (1988) Biochemistry 27:5906.
- van Dalen, C.J. et al. (2000) J. Biol. Chem. 275:11638.
- Hazen, S.L. and J.W. Heinecke (1997) J. Clin. Invest. 99:2075.
- Heinecke, J.W. et al. (1993) J. Clin. Invest. 91:2866.
- Podrez, E.A. et al. (1999) J. Clin. Invest. 103:1547.
- Bergt, C. et al. (2004) Proc. Natl. Acad. Sci. 101:13032.
- Hazen, S.L. et al. (1996) J. Biol. Chem. 271:23080.
- Eiserich, J.P. et al. (2002) Science 296:2391.
- Tiruppathi, C. et al. (2004) Proc. Natl. Acad. Sci. 101:7699.
- Aratani Y. et al. (2000) J. Infect. Dis. 182:1276.
- Kutter, D. (1998) J. Mol. Med. 76:669.
Citations for Recombinant Human Myeloperoxidase Protein, CF
R&D Systems personnel manually curate a database that contains references using R&D Systems products. The data collected includes not only links to publications in PubMed, but also provides information about sample types, species, and experimental conditions.
Citations: Showing 1 - 8
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Immune Regulation of Mammary Fibroblasts and the Impact of Mammographic Density
Authors: M Archer, P Dasari, D Walsh, KL Britt, A Evdokiou, WV Ingman
Journal of Clinical Medicine, 2022;11(3):.
Sample Types: Whole Cells
DNA interstrand cross-links induced by the major oxidative adenine lesion 7,8-dihydro-8-oxoadenine
Authors: AL Rozelle, Y Cheun, CK Vilas, MC Koag, S Lee
Nature Communications, 2021;12(1):1897.
Sample Types: DNA
Response of Human Neutrophil Granulocytes to the Hyphae of the Emerging Fungal Pathogen Curvularia lunata
Authors: EJ Tóth, M Varga, M Takó, M Homa, O Jáger, E Hermesz, H Orvos, G Nagy, C Vágvölgyi, T Papp
Sample Types: Reference Standard
A Structurally Dynamic N-terminal Region Drives Function of the Staphylococcal Peroxidase Inhibitor (SPIN)
Authors: NWM de Jong, NT Ploscariu, KX Ramyar, BL Garcia, AI Herrera, O Prakash, BB Katz, KG Leidal, WM Nauseef, KPM van Kessel, JAG van Strijp, BV Geisbrecht
J. Biol. Chem., 2018;0(0):.
Sample Types: Recombinant Protein
Identification and structural characterization of a novel myeloperoxidase inhibitor from Staphylococcus delphini
Authors: NT Ploscariu, NWM de Jong, KPM van Kessel, JAG van Strijp, BV Geisbrecht
Arch. Biochem. Biophys., 2018;645(0):1-11.
Species: Bacteria - Staphylococcus aureus
Sample Types: Recombinant Protein
Immune evasion by a staphylococcal inhibitor of myeloperoxidase
Authors: NWM de Jong, KX Ramyar, FE Guerra, R Nijland, C Fevre, JM Voyich, AJ McCarthy, BL Garcia, KPM van Kessel, JAG van Strijp, BV Geisbrecht, PA Haas
Proc. Natl. Acad. Sci. U.S.A., 2017;0(0):.
Species: Bacteria - Staphylococcus aureus
Sample Types: Cell Culture Supernates
Gut Microbiota Conversion of Dietary Ellagic Acid into Bioactive Phytoceutical Urolithin A Inhibits Heme Peroxidases
PLoS ONE, 2016;11(6):e0156811.
Sample Types: Protein
Applications: Enzyme Assay
A novel zebrafish model to provide mechanistic insights into the inflammatory events in carrageenan-induced abdominal edema.
Authors: Huang S, Feng C, Hung H, Chakraborty C, Chen C, Chen W, Jean Y, Wang H, Sung C, Sun Y, Wu C, Liu W, Hsiao C, Wen Z
PLoS ONE, 2014;9(8):e104414.
Sample Types: N/A
Applications: Western Blot
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Reviews for Recombinant Human Myeloperoxidase Protein, CF
Average Rating: 5 (Based on 2 Reviews)
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The protein was used as a calibrator in an in vitro immunoassay.
Reason for Rating: Very stable protein