Description

Stefin A is a potent and specific cysteine protease inhibitor belonging to the cystatin superfamily, widely recognized for its role in regulating proteolytic activity. This high-purity biochemical is essential for researchers and manufacturers requiring precise control over cathepsin-mediated processes in complex biological systems. It is a critical reagent for applications in biomedical research, pharmaceutical development, and diagnostic assay formulation, where its inhibitory specificity is paramount.

Application

• Biomedical Research: Used as a specific inhibitor to study the role of cysteine proteases like cathepsins B, H, and L in cellular processes, including apoptosis, protein turnover, and disease mechanisms.
• Pharmaceutical Development: Serves as a reference standard and tool compound in drug discovery programs targeting protease-related disorders such as osteoporosis, arthritis, and cancer metastasis.
• Diagnostic Kit Manufacturing: Incorporated into enzymatic assay kits to selectively inhibit background cysteine protease activity, ensuring assay specificity and accuracy.
• Biochemical Reagent: Employed in in vitro experiments to protect proteins of interest from unwanted degradation during extraction, purification, and analysis.
• Cell Culture Studies: Applied to cell culture media to investigate the effects of inhibiting intracellular cysteine proteases on cell behavior and signaling pathways.

Basic Information

Product Name	Stefin A
CAS No.	107544-29-6
Molecular Formula	C76H122N22O22
Molecular Weight	1648.9 g/mol
Synonyms	Cystatin A; Acid Cysteine Proteinase Inhibitor; CPI; STF1; STFA; Stefin-A; Cystatin, Acid; Human Cystatin A; Cysteine Protease Inhibitor A
EINECS	Contact for details

Quality Control

Our Stefin A is produced under stringent conditions to ensure the highest standards of purity and biological activity. Each batch is subjected to comprehensive analytical testing, including HPLC for purity verification, mass spectrometry for identity confirmation, and functional activity assays. Certificates of Analysis (COA) detailing all specifications are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below. This product is hygroscopic (moisture-sensitive). Allow the vial to reach room temperature in a desiccator before opening to prevent condensation and moisture uptake.

Specification

Item	Specification
Appearance	White to off-white lyophilized powder
Identification (HPLC/MS)	Conforms to reference standard
Purity (HPLC)	≥ 95%
Biological Activity	≥ 90% of stated inhibitory activity
Water Content (KF)	≤ 5.0 %
Endotoxin	< 1.0 EU/μg

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.