Human Latexin, also known as tissue carboxypeptidase inhibitor, is the only mammalian carboxypeptidase inhibitor identified so far. Latexin was initially identified as a marker of neurons in the lateral neocortex of the developing brain (hence latexin) (1). Further studies have shown that latexin is highly expressed in mast cells and macrophages (2, 3). It is induced in acute pancreatitis and lung inflammatory disease. In addition, it is able to inhibit carboxypeptidases from the pancreas (CPA1 and CPA2) and mast cells (CPA3) (4). Therefore, it is thought that latexin primarily functions in inflammation and innate immunity pathways. Compared to other carboxypeptidase inhibitors from plants and parasites, the 222 amino acid latexin is much larger and more importantly, it lacks some conserved C-terminal residues, which interact with the target carboxypeptidase in a substrate-like manner (5). This distinct feature of latexin suggests that it has a different carboxypeptidase inhibition mechanism.
Recombinant Human Latexin Protein, CF
R&D Systems | Catalog # 3246-PI
Loading...
Key Product Details
- R&D Systems E. coli-derived Recombinant Human Latexin Protein (3246-PI)
- Quality control testing to verify active proteins with lot specific assays by in-house scientists
- All R&D Systems proteins are covered with a 100% guarantee
Source
E. coli
Accession Number
Applications
Inhibition Activity
Loading...
Product Specifications
Source
E. coli-derived human Latexin protein
Glu2-Glu222, with an N-terminal Met and 6-His tag
Glu2-Glu222, with an N-terminal Met and 6-His tag
Purity
>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
Endotoxin Level
<1.0 EU per 1 μg of the protein by the LAL method.
N-terminal Sequence Analysis
Met
Predicted Molecular Mass
27 kDa
SDS-PAGE
30 kDa, reducing conditions
Activity
Measured by its ability to inhibit carboxypeptidase A1 cleavage of the colorimetric peptide substrate Ac-Phe-Thiaphe-OH in the presence of 5,5’Dithio-bis (2-nitrobenzoic acid) (DTNB). Edwards, K.M. et al. (1999) J. Biol. Chem. 274:30468.
The IC50 value is <1 nM, as measured under the described conditions.
The IC50 value is <1 nM, as measured under the described conditions.
Formulation, Preparation, and Storage
3246-PI
| Formulation | Supplied as a 0.2 μm filtered solution in Tris and NaCl. |
| 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.
|
Background: Latexin
References
- Arimatsu, Y. et al. (1994) Neurosci. Res. 20:131.
- Uratani, Y. et al. (2000) Biochem. J. 346:817.
- Aagaard, A. et al. (2005) Structure 13:309.
- Normant, E. et al. (1995) Proc. Natl. Acad. Sci. USA 92:12225.
- Reverter, D. et al. (2000) Nat. Struct. Biol. 7:322.
Alternate Names
ECI, LXN, TCI
Gene Symbol
LXN
UniProt
Additional Latexin Products
Product Documents for Recombinant Human Latexin Protein, CF
Certificate of Analysis
To download a Certificate of Analysis, please enter a lot or batch number in the search box below.
Note: Certificate of Analysis not available for kit components.
Product Specific Notices for Recombinant Human Latexin Protein, CF
For research use only
Related Research Areas
Customer Reviews for Recombinant Human Latexin Protein, CF
There are currently no reviews for this product. Be the first to review Recombinant Human Latexin Protein, CF and earn rewards!
Have you used Recombinant Human Latexin Protein, CF?
Submit a review and receive an Amazon gift card!
$25/€18/£15/$25CAN/¥2500 Yen for a review with an image
$10/€7/£6/$10CAN/¥1110 Yen for a review without an image
Submit a review
Protocols
View specific protocols for Recombinant Human Latexin Protein, CF (3246-PI):
Materials
- Assay Buffer: 50 mM Tris, 150 mM NaCl, 10 mM CaCl2, 0.05% Brij-35, pH 7.5 (TCNB)
- Recombinant Human Latexin (rhLatexin) (Catalog # 3246-PI)
- Recombinant Human Carboxypeptidase A1/CPA1 (rhCPA1) (Catalog # 2856-ZN)
- Trypsin (Sigma, Catalog # T-1426)
- Substrate: Ac-Phe-Thiaphe-OH (Peptides International, Catalog # STP-3621-PI),10 mM stock in DMSO
- 5,5’-dithio-bis(2-nitrobenzoic acid) (DTNB), (Sigma, Catalog # D-8130) 10 mM stock in DMSO
- 96 well clear plate (Costar, Catalog # 92592)
- Plate Reader (Model: SpectraMax Plus by Molecular Devices) or equivalent
- Dilute rhCPA1 to 100 µg/mL with 1 µg/mL Trypsin in Assay Buffer.
- Incubate at room temperature for 1 hour.
- Dilute active rhCPA1 to 20 µg/mL in Assay Buffer.
- Prepare a curve of rhLatexin (MW: 26,575 Da) in assay buffer. Make the following serial dilutions: 1600, 800, 400, 200, 150, 100, 50, and 25 nM.
- Mix equal volumes of the rhLatexin curve dilutions and the diluted rhCPA-1. Include a control (in duplicate) containing Assay Buffer and the diluted rhCPA-1.
- Incubate mixtures at 37 °C for 1 hour.
- After incubation, dilute the mixtures by 50 fold in Assay Buffer.
- Combine equal volumes of Substrate and DTNB. Dilute this mixture to 200 µM Substrate and 200 µM DTNB in Assay Buffer.
- Load 50 µL of the incubated mixtures into the plate, and start the reaction by adding 50 µL of 200 µM Substrate mixture.
- Read in kinetic mode for 5 minutes at an absorbance of 405 nm.
- Derive the 50% inhibition concentration (IC50) for rhLatexin by plotting OD/min (or specific activity) vs. concentration with 4-PL fitting.
- The specific activity for rhCPA1 at each point may be determined using the following formula (if needed):
|
Specific Activity (pmol/min/µg) = |
Adjusted Vmax* (OD/min) x well volume (L) x 1012 pmol/mol |
| ext. coeff** (M-1cm-1) x path corr.*** (cm) x amount of enzyme (µg) |
*Adjusted for Substrate Blank
**Using the extinction coefficient 13260 M-1cm-1
***Using the path correction 0.32 cm
Note: the output of many spectrophotometers is in mOD Per Well:
- rhCPA1: 0.010 µg
- rhLatexin curve: 8, 4, 2.0, 1.0, 0.75, 0.5, 0.25, and 0.125 nM.
- Substrate: 100 µM
- DTNB: 100 µM
Loading...