Recombinant Mouse Cathepsin D Protein, CF

• 6 months from date of receipt, -20 to -70 °C as supplied.
• 3 months, -20 to -70 °C under sterile conditions after reconstitution.

• Assay Buffer: 0.1 M Sodium Acetate, 0.2 M NaCl, pH 3.5
• Recombinant Mouse Cathepsin D (rmCathepsin D) (Catalog # 1029-AS)
• Substrate: MCA-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH₂ (Catalog # ES001)
• F16 Black Maxisorp Plate (Nunc, Catalog # 475515)
• Fluorescent Plate Reader (Model: SpectraMax Gemini EM by Molecular Devices) or equivalent

1. Dilute rmCathepsin D to 20 µg/mL in Assay Buffer.
2. Incubate at RT for 10 minutes.
3. Dilute activated rmCathepsin D to 0.4 ng/µL in Assay Buffer.
4. Dilute Substrate to 20 µM in Assay Buffer.
5. Load 50 µL of the 0.4 ng/µL rmCathepsin D in a plate, and start the reaction by adding 50 µL of 20 µM Substrate. Include a Substrate Blank containing 50 µL Assay Buffer and 50 µL of 20 µM Substrate.
6. Read at excitation and emission wavelengths of 320 nm and 405 nm (top read), respectively in kinetic mode for 5 minutes.
7. Calculate specific activity:

     *Adjusted for Substrate Blank
     **Derived using calibration standard MCA-Pro-Leu-OH (Bachem, Catalog # M-1975)

• rmCathepsin D: 0.020 µg
• Substrate: 10 µM