Recombinant Human Cystatin-SN (CST1)

Uniprot Id

P01037

Target Species

Human

Target Name

CST1

Target Full Name

Cystatin-SN

Target Function

Human saliva appears to contain several cysteine proteinase inhibitors that are immunologically related to cystatin S but that differ in their specificity due to amino acid sequence differences. Cystatin SN, with a pI of 7.5, is a much better inhibitor of papain and dipeptidyl peptidase I than is cystatin S, although both inhibit ficin equally well.

Target Subcellular Location

Secreted.

Target Protein Families

Cystatin family

Target Tissue Specificity

Expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). Expressed in saliva, tears, urine and seminal fluid.

Target Synonyms

CST1; Cystain SAI; Cystain-SA-I; Cystatin 1; Cystatin-1; Cystatin-SN; Cystatin1; Cysteine proteinase inhibitor, type 2 family; CYTN; CYTN_HUMAN; Salivary cystatin SA1; Salivary cystatin-SA-1

Target Background

The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions, where they appear to provide protective functions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This gene is located in the cystatin locus and encodes a cysteine proteinase inhibitor found in saliva, tears, urine, and seminal fluid.