Human Cystatin S / CST4 Gene ORF cDNA clone expression plasmid,C terminal Flag tag

Gene

Species

Human

NCBI Ref Seq

NM_001899.2

RefSeq ORF Size

426bp

Gene Synonym

MGC71923, CST4

Sequence Description

Identical with the Gene Bank Ref. ID sequence.

Description

Full length Clone DNA of Human cystatin S Gene ORF cDNA clone expression plasmid,C terminal Flag tag

Plasmid

Promoter

Enhanced CMV mammalian cell promoter

Vector

pCMV3-C-FLAG

Restriction Site

Protein Tag

Flag

Tag Sequence

GATTACAAGGATGACGACGATAAG

Sequencing Primers

Forward:T7(TAATACGACTCACTATAGGG) Reverse:BGH(TAGAAGGCACAGTCGAGG)

Quality Control

The plasmid is confirmed by full-length sequencing.

Flag Tag Information

FLAG-tag, or FLAG octapeptide, is a polypeptide protein tag that can be added to a protein using recombinant DNA technology. It can be used for affinity chromatography, then used to separate recombinant, overexpressed protein from wild-type protein expressed by the host organism. It can also be used in the isolation of protein complexes with multiple subunits.

A FLAG-tag can be used in many different assays that require recognition by an antibody. If there is no antibody against the studied protein, adding a FLAG-tag to this protein allows one to follow the protein with an antibody against the FLAG sequence. Examples are cellular localization studies by immunofluorescence or detection by SDS PAGE protein electrophoresis.

The peptide sequence of the FLAG-tag from the N-terminus to the C-terminus is: DYKDDDDK (1012 Da). It can be used in conjunction with other affinity tags, for example a polyhistidine tag (His-tag), HA-tag or myc-tag. It can be fused to the C-terminus or the N-terminus of a protein. Some commercially available antibodies (e.g., M1/4E11) recognize the epitope only when it is present at the N-terminus. However, other available antibodies (e.g., M2) are position-insensitive.

Screening

Antibiotic in E.coli

Kanamycin

Antibiotic in Mammalian cell

Hygromycin

Application

Stable or Transient mammalian expression

Storage & Shipping

Shipping

Each tube contains lyophilized plasmid.

Storage

The lyophilized plasmid can be stored at ambient temperature for three months.

Other Life Science vendor

Natural small molecules manufacturer | Biological Research Reagents Manufacturer

Background Information

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.

References

Catalog Number:HGC025-CF