|Datasheet||Specific References||Reviews||Related Products||Protocols|
|Vector Type||Mammalian Expression Vector|
|Expression Method||Constiutive, Stable / Transient|
|Selection In Mammalian Cells||Hygromycin|
A polyhistidine-tag is an amino acid motif in proteins that consists of at least five histidine (His) residues, often at the N- or C-terminus of the protein.
Polyhistidine-tags are often used for affinity purification of polyhistidine-tagged recombinant proteins expressed in Escherichia coli and other prokaryotic expression systems.
|Human CST4 ORF mammalian expression plasmid, C-GFPSpark tag||HG11542-ACG|
|Human CST4 ORF mammalian expression plasmid, C-OFPSpark / RFP tag||HG11542-ACR|
|Human CST4 ORF mammalian expression plasmid, C-Flag tag||HG11542-CF|
|Human CST4 ORF mammalian expression plasmid, C-His tag||HG11542-CH|
|Human CST4 ORF mammalian expression plasmid, C-Myc tag||HG11542-CM|
|Human CST4 ORF mammalian expression plasmid, C-HA tag||HG11542-CY|
|Human CST4 Gene cDNA clone plasmid||HG11542-M|
|Human CST4 natural ORF mammalian expression plasmid||HG11542-M-N|
|Human CST4 ORF mammalian expression plasmid, N-Flag tag||HG11542-NF|
|Human CST4 ORF mammalian expression plasmid, N-His tag||HG11542-NH|
|Human CST4 ORF mammalian expression plasmid, N-Myc tag||HG11542-NM|
|Human CST4 ORF mammalian expression plasmid, N-HA tag||HG11542-NY|
|Human CST4 natural ORF mammalian expression plasmid||HG11542-UT|
|Learn more about expression Vectors|
Cystatin-S, also known as Cystatin-4, Salivary acidic protein 1, Cystatin-SA-III and CST4, is a secreted protein which belongs to the cystatin 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.