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Recombinant Human Cystatin A Protein, CF

Bio-Techne includes R&D Systems | Catalog # 1407-PI

Catalog #
Size / Price

Key Product Details


E. coli

Accession #




Inhibition Activity

Product Specifications


E. coli-derived human Cystatin A protein
Ile2-Phe98, with an N-terminal Met and 6-His tag


>95%, by SDS-PAGE under reducing conditions and visualized by silver stain.

Endotoxin Level

<1.0 EU per 1 μg of the protein by the LAL method.

N-terminal Sequence Analysis


Predicted Molecular Mass

12 kDa


12 kDa, reducing conditions


Measured by its ability to inhibit papain cleavage of a fluorogenic peptide substrate Z-FR-AMC (Catalog # ES009).
The IC50 value is <3.4 nM, as measured under the described conditions.

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in Tris and NaCl.
Reconstitution Reconstitute at 100 μg/mL in sterile 25 mM Tris and 100 mM NaCl, pH 7.5.
Shipping The product is shipped at ambient temperature. 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.

Background: Cystatin A

Cystatin A, also called stefin A, Cystatin AS or keratolinin, is a member of family 1 of the cystatin superfamily (1, 2). Like Cystatin B, it is an intracellular inhibitor regulating the activities of cysteine proteases of the papain family such as cathepsins B, H and L (3). For example, immunohistochemical analysis of Cystatin A and cathepsin L is a useful indicator for malignancy in human epidermal keratinocytes (4). The ratio of cathepsin B and Cystatin A can be used in the differential diagnosis and treatment of patients with prostate carcinoma (5). The human Cystatin A consists of 98 amino acids (1).


  1. Kartasova, T. et al. (1987) Nucleic Acids Res. 15:5945.
  2. Abrahamson, M. (1994) Methods Enzymol. 244:685.
  3. Jenko, S. et al. (2003) J. Mol. Biol. 326:875.
  4. Palungwachira, P. et al. (2002) J. Dermatol. 29:573.
  5. Sinha, A.A. et al. (2002) Cancer 94:3141.

Alternate Names


Entrez Gene IDs

1475 (Human)

Gene Symbol



Additional Cystatin A Products

Product Documents for Recombinant Human Cystatin A Protein, CF

Certificate of Analysis

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Product Specific Notices for Recombinant Human Cystatin A Protein, CF

For research use only

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