Recombinant Human Kallikrein 3/PSA Protein, CF

Catalog # Availability Size / Price Qty
Recombinant Human Kallikrein 3/PSA Protein Enzyme Activity
1 Image
Product Details
Citations (5)
Supplemental Products
Reviews (1)

Recombinant Human Kallikrein 3/PSA Protein, CF Summary

Product Specifications

>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.
Measured by its ability to cleave the colorimetric peptide substrate, Succinyl-Arg-Pro-Tyr-p-Nitroanilide (Suc-RPY-pNA). The specific activity is >70 pmol/min/µg, as measured under the described conditions.
Mouse myeloma cell line, NS0-derived human Kallikrein 3/PSA protein
Ala18-Pro261, with a C-terminal 10-His tag
Accession #
N-terminal Sequence
Structure / Form
Pro form
Predicted Molecular Mass
28 kDa
36 kDa, reducing conditions

Product Datasheets

You must select a language.



Carrier Free

What does CF mean?

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.

What formulation is right for me?

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, NaCl and CaCl2.
Reconstitution Reconstitute at 200 μg/mL in 50 mM Tris, 10 mM CaCl2,150 mM NaCl and 0.05% (w/v) Brij-35, pH 7.5.
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.
  • 6 months from date of receipt, -20 to -70 °C as supplied.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Assay Procedure

  • Activation Buffer: 50 mM Tris, 10 mM CaCl2, 150 mM NaCl, 0.05% Brij-35, pH 7.5 (TCNB)
  • Assay Buffer: 50 mM Tris, 1 M NaCl, pH 8.0
  • Recombinant Human Kallikrein 3/PSA (rhKLK3) (Catalog # 1344-SE)
  • Bacterial Thermolysin (Thermolysin) (Catalog # 3097-ZN)
  • 1,10 Phenanthroline (Sigma, Catalog # 320056), 0.6 M stock in DMSO
  • Substrate: Suc-Arg-Pro-Tyr-pNa (AnaSpec, Catalog # 20586), 10 mM in deionized water
  • 96-well Clear Plate (Costar, Catalog # 92592)
  • Plate reader (Model: SpectraMax Plus by Molecular Devices) or equivalent
  1. Dilute rhKLK3 to 200 µg/mL in Activation Buffer.
  2. Dilute Thermolysin to 2 µg/mL in Activation Buffer.
  3. Combine equal volumes of 200 µg/mL rhKLK3 and 2 µg/mL Thermolysin.
  4. Incubate at 37 °C for 5 minutes.
  5. Dilute 1,10 Phenanthroline to 20 mM in Assay Buffer.
  6. Stop Thermolysin activity  by adding 1,10 Phenanthroline to a final concentration of 10 mM.
  7. Dilute activated rhKLK3 to 20 ng/µL in Assay Buffer.
  8. Dilute Substrate to 2 mM in Assay Buffer.
  9. Load 50 µL of the 20 ng/µL rhKLK3 in a plate and start the reaction by adding 50 µL of 2 mM Substrate. Include a Substrate Blank containing 50 µL Assay Buffer and 50 µL of 2 mM Substrate.
  10. Read at a wavelength of 405 nm (bottom read) in kinetic mode for 5 minutes.
  11. Calculate specific activity:

     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 8800 M-1cm-1 
     ***Using the path correction 0.32 cm
     Note: the output of many spectrophotometers is in mOD. Per Well:
  • rhKLK3: 1 µg
  • Substrate: 1 mM

Scientific Data

Enzyme Activity Recombinant Human Kallikrein 3/PSA Protein Enzyme Activity View Larger

Recombinant Human Kallikrein 3 (Catalog # 1344-SE) is measured by its ability to cleave the colorimetric peptide substrate, Succinyl-Arg-Pro-Tyr-p-Nitroanilide (Suc-RPY-pNA).

Reconstitution Calculator

Reconstitution Calculator

The reconstitution calculator allows you to quickly calculate the volume of a reagent to reconstitute your vial. Simply enter the mass of reagent and the target concentration and the calculator will determine the rest.


Background: Kallikrein 3/PSA

Kallikrein 3, commonly known as prostate specific antigen (PSA), is a serine protease of the human tissue Kallikrein gene family (1). PSA is synthesized in the ductal and acinar epithelium of the prostate gland and secreted into the seminal plasma in high concentrations (0.5 - 2 g/L) (2). A small portion of PSA “leaks” into the systemic circulation, the levels of which increase significantly (30-fold) from prostate cancer tissue than normal prostate tissue (3). PSA has become a well established tumor marker that aids the diagnosis, staging, and follow up of prostate cancer.

The deduced amino acid sequence of human PSA consists of a signal peptide, a short pro region and a mature/active enzyme. The pro-enzyme is activated, possibly by active Kallikreins 2, 4 or 15 in vivo (4). rhPSA is activated by thermolysin, a zinc protease. The active PSA cleaves several tyrosyl peptide bonds in semenogelins I and II, which are the major gel-forming proteins produced by the seminal vesicles (5). Several inhibitors including serpin A3/ alpha 1-antichymotrypsin (ACT) and alpha 2‑macroglobulin are known to form complexes with PSA.

  1. Yousef, G.M. and E.P. Diamandis (2001) Endocrine Rev. 22:184.
  2. Ward, A.M. et al. (2001) Ann. Clin. Biochem. 38:633.
  3. Jain, S. et al. (2002) Postgrad. Med. J. 78:646.
  4. LiLja H. (2003) Urology 62:27.
  5. Takayama, T.K. et al. (1997) J. Biol. Chem. 272:21582.
Entrez Gene IDs
354 (Human)
Alternate Names
APS seminin; EC 3.4.21; EC; Gamma-seminoprotein; hK3; Kallikrein 3; kallikrein 3, (prostate specific antigen); Kallikrein-3; kallikrein-related peptidase 3; KLK2A1; KLK3; P-30 antigen; prostate specific antigen; prostate-specific antigen; PSA semenogelase; PSA; Semenogelase; Seminin

Citations for Recombinant Human Kallikrein 3/PSA 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.

5 Citations: Showing 1 - 5
Filter your results:

Filter by:

  1. Protein detection in blood with single-molecule imaging
    Authors: CP Mao, SC Wang, YP Su, SH Tseng, L He, AA Wu, RBS Roden, J Xiao, CF Hung
    Science Advances, 2021;7(33):.
    Species: Human
    Sample Types: Reference Standard
  2. Activation of hepatocyte growth factor activator zymogen (pro-HGFA) by human kallikrein 1-related peptidases.
    Authors: Mukai S, Fukushima T, Naka D, Tanaka H, Osada Y, Kataoka H
    FEBS J., 2008;275(5):1003-17.
    Species: Human
    Sample Types: Protein
    Applications: Enzyme Assay
  3. Quantum dot-based protein micro- and nanoarrays for detection of prostate cancer biomarkers.
    Authors: Gokarna A, Jin LH, Hwang JS, Cho YH, Lim YT, Chung BH, Youn SH, Choi DS, Lim JH
    Proteomics, 2008;8(9):1809-18.
    Species: Human
    Sample Types: Recombinant Protein
    Applications: Bioassay
  4. Activation profiles and regulatory cascades of the human kallikrein-related peptidases.
    Authors: Yoon H, Laxmikanthan G, Lee J, Blaber SI, Rodriguez A, Kogot JM, Scarisbrick IA, Blaber M
    J. Biol. Chem., 2007;282(44):31852-64.
    Species: N/A
    Sample Types: Peptide
    Applications: Enzyme Assay
  5. Inhibition of kallikrein-related peptidases by the serine protease inhibitor of Kazal-type 6.
    Authors: Kantyka T, Fischer J, Wu Z, Declercq W, Reiss K, Schroder J, Meyer-Hoffert U
    Peptides, 0;32(6):1187-92.
    Species: Human
    Sample Types: Enzyme Substrate


No product specific FAQs exist for this product, however you may

View all Proteins and Enzyme FAQs

Reviews for Recombinant Human Kallikrein 3/PSA Protein, CF

Average Rating: 5 (Based on 1 Review)

5 Star
4 Star
3 Star
2 Star
1 Star

Have you used Recombinant Human Kallikrein 3/PSA Protein, CF?

Submit a review and receive an Amazon gift card.

$25/€18/£15/$25CAN/¥75 Yuan/¥1250 Yen for a review with an image

$10/€7/£6/$10 CAD/¥70 Yuan/¥1110 Yen for a review without an image

Submit a Review

Filter by:

Recombinant Human Kallikrein 3/PSA Protein, CF
By Anonymous on 08/10/2017
Application: Enzymatic activity in vitro