Name :
Recombinant Human Cystatin S Protein (His Tag)

Biological Activity :

Background :
Cystatin-S, also known as Cystatin-4, Salivary acidic protein 1, Cystatin-SA-III and CST4, is a secreted protein which belongs to thecystatin family. Cystatin-4 / CST4 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). It is also expressed in saliva, tears, urine and seminal fluid. 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. Cystatin-4 / CST4 strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively. Cystatin-4 / CST4 is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function.

Biological Activity :
Testing in progress

Expression Host :
Human

Source :
HEK293 Cells

Tag :

Protein Accession No. :
NP_001890.1

NCBI Gene ID :

Synonyms :

Synonyms :
Cystatin S

Amino Acid Sequence :

Molecular Weight :
The secreted recombinant human CST4 consists of 132 amino acids and migrates as an approximately 16 kDa band in SDS-PAGE under reducing conditions as predicted.

Purity :
> 98 % as determined by SDS-PAGE

State of Matter :

Product Concentration :

Storage and Stability :
Samples are stable for up to twelve months from date of receipt at -20℃ to -80℃. Store it under sterile conditions at -20℃ to -80℃. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.

Endotoxin Level :
< 1.0 EU per μg of the protein as determined by the LAL method

Protein Construction :
A DNA sequence encoding the human CST4 (NP_001890.1) (Met 1-Ala 141) was fused with a polyhistidine tag at the C-terminus.

Buffer Solution :
Lyophilized from sterile PBS, pH 7.4.Please contact us for any concerns or special requirements. Normally 5 % – 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization. Please refer to the specific buffer information in the hardcopy of datasheet.

Shipping :
In general, recombinant proteins are provided as lyophilized powder which are shipped at ambient temperature.Bulk packages of recombinant proteins are provided as frozen liquid. They are shipped out with blue ice unless customers require otherwise.

Redissolution :
A hardcopy of datasheet with reconstitution instructions is sent along with the products. Please refer to it for detailed information.

Synonyms :
CST4 Protein, Human; MGC71923 Protein, Human Cystatin S 背景信息 Cystatin-S, also known as Cystatin-4, Salivary acidic protein 1, Cystatin-SA-III and CST4, is a secreted protein which belongs to thecystatin family. Cystatin-4 / CST4 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). It is also expressed in saliva, tears, urine and seminal fluid. 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. Cystatin-4 / CST4 strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively. Cystatin-4 / CST4 is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function.

References & Citations :
Bobek L.A., et al.,(1991), Human salivary Cystatin S. Cloning, sequence analysis, hybridization in situ and immunocytochemistry. Biochem. J. 278:627-635.Saitoh E., et al., (1992), Characterization of two members (CST4 and CST5) of the cystatin gene family and molecular evolution of cystatin genes.Agents Actions 38:340-348.Deloukas P., et al.,(2001), The DNA sequence and comparative analysis of human chromosome 20.Nature 414:865-871.

MedChemExpress (MCE) recombinant proteins include: cytokines, enzymes, growth factors, hormones, receptors, transcription factors, antibody fragments, etc. They are often essential for supporting cell growth, stimulating cell signaling pathways, triggering or inhibiting cell differentiation; and are useful tools for elucidating protein structure and function, understanding disease onset and progression, and validating pharmaceutical targets. At MedChemExpress (MCE), we strive to provide products with only the highest quality. Protein identity, purity and biological activity are assured by our robust quality control and assurance procedures.
Related category websites: https://www.medchemexpress.com/recombinant-proteins.html
Popular product recommendations:
ST2/IL1RL1 Protein
HGFR Protein
Popular categories:
IgE
MASP-1