Active Human Caspase-1

UNIT DEFINATION:

One unit of the recombinant caspase-1 is the enzyme activity that cleaves 1 nmol of the caspase substrate YVAD-pNA (pNA: pnitroanaline) per hour at 37^oC in a reaction solution containing 50 mM Hepes, pH 7.2, 50 mM NaCl, 0.1% Chaps, 10 mM EDTA, 5% Glycerol, and 10 mM DTT.

FORM: Lyophilized powder

RECONSTITUTION: Reconstitute to 1 unit per ìl in PBS containing 15% glycerol.

SPECIFIC ACTIVITY: 20000 units/mg

STORAGE CONDITIONS:

The lyophilized caspase-1 is stable for 1 year at –70^oC. Following reconstitution in PBS, the enzyme should be aliquoted and immediately stored at –70^oC. Avoid multiple freeze/thaw cycles as activity might decrease.

DESCRIPTION:

Caspase-1 (also know as ICE) is a prototypical member of the caspase-family of cysteine proteases. Caspase-1 exists in cells as an inactive 45 kDa proenzyme. The pro-enzyme is matured by proteolysis to yield large (20 kD) and small (10 kD) subunits. The active caspase1 is a heterotetramer consisting of two large and two small subunits. To date the regulatory mechanism of caspase-1 activation and the role of caspase-1 in apoptosis are poorly understood. In THP-1 cells, a large proportion of the caspase-1 is present in the inactive proenzyme form.

The recombinant active human caspase-1 was expressed in E. coli. The active caspase-1 preferentially cleaves caspase-1 substrates (e.g., YVAD-AFC or YVAD-pNA) and is routinely tested at BioVision for its ability to enzymatically cleave these two substrates Ac-YVAD-pNA (Cat. #1104-200) or Ac-YVAD-AFC (1103-200).

APPLICATIONS AND USAGE:

Active caspase-1 is useful in studying enzyme regulation, determining target substrates, screening caspase inhibitors, or as a positive control in caspase activity assays. We recommend using 1 unit/assay for analyzing caspase activity.

For a complete caspase-1 assay protocol, please refer to BioVision’s Caspase-1 Fluorometric or Colorimetric Assay Kits (Cat.#: K110 and K111).

Quality Antibodies for Apoptosis and Signal Transduction Molecules