CST1 Human

Cystatin SN is produced primarily by the salivary glands and is secreted largely in the submandibular and sublingual saliva . It is also found in other bodily fluids such as tears, urine, and seminal fluid . The protein consists of 141 amino acids and has a molecular weight of approximately 16 kDa .

The primary function of Cystatin SN is to inhibit the activity of cysteine proteases, particularly those in the papain family, including cathepsins B, C, H, and L . These enzymes are involved in various physiological processes, including protein degradation, immune response, and cellular turnover. By inhibiting these enzymes, Cystatin SN helps to regulate their activity and prevent excessive protein breakdown.

Recombinant human Cystatin SN is produced using various expression systems, including Escherichia coli and mouse myeloma cell lines . The recombinant form is often tagged with a His-tag to facilitate purification and is typically purified to a high degree of purity (>95%) for research and clinical applications .

Recombinant Cystatin SN is used in various research applications, including studies on enzyme regulation, protein-protein interactions, and the role of cysteine protease inhibitors in disease processes. It is also used in the development of diagnostic assays and therapeutic interventions targeting cysteine proteases .

Recombinant Cystatin SN is typically lyophilized and can be reconstituted in a suitable buffer for use in experiments. It is stable for several months when stored at -20 to -70°C and should be handled carefully to avoid repeated freeze-thaw cycles .