• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to inhibit rmGDF-8 activity in K562 human chronic myelogenous leukemia cells. The ED    ₅₀ for this effect is 0.03-0.15 µg/mL, in the presence of 40 ng/mL of rmGDF-8. Measured by its ability to inhibit trypsin cleavage of a fluorogenic peptide substrate, Mca-RPKPVE-Nval-WRK(Dnp)-NH    ₂ (Catalog # ). The IC    ₅₀ value is approximately 1.5 nM, as measured in a reaction mixture containing 1.0 nM trypsin,10 mM ES002, 50 mM Tris, 10 mM CaCl    ₂, 0.15 M NaCl, pH 7.5.

• Source

  Mouse myeloma cell line, NS0-derived Leu35-His576, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Leu35

• Predicted Molecular Mass

  60.7 kDa

• SDS-PAGE

  75-80 kDa, reducing conditions

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: GASP-1/WFIKKNRP

Growth and differentiation factor-associated serum protein-1 (GASP-1) was isolated in a screen to identify proteins in mice that copurify with myostatin (GDF-8), a potent negative regulator of skeletal muscle mass (1). The GASP-1 cDNA encodes a 571 amino acid protein that contains a 29 amino acid signal sequence and is comprised of many conserved domains: WAP, follistatin/Kazal, immunoglobulin, two tandem Kunitz, and netrin (1). Two related human proteins which contain the same domain structure are called WFIKKN (based on the presence and order of these conserved domains) and WFIKKNRP (WFIKKN-related protein) (2). Mouse GASP-1 is homologous to human WFIKKNRP and mouse GASP-2 to human WFIKKN. Human GASP-1 is the same protein as WFIKKNRP.

WAP, follistatin, Kazal and netrin domains are all implicated in protease inhibition, and these proteins may be multivalent protease inhibitors (3). GASP-1 and -2 show distinct expression patterns both in the developing fetus and the adult. In the developing fetus, GASP-1 expression is highest in the brain, skeletal muscle, thymus and kidney while GASP-2 is abundant in the lung, skeletal muscle and liver (4). In the adult, GASP-1 is primarily expressed in the ovary, testis, and brain while GASP-2 is in the pancreas, liver, and thymus (4). GASP-1 inhibits myostatin and the highly related protein, GDF-11, but not Activin or TGF-beta in vitro (1). In addition, GASP-1 binds directly but independently to both mature myostatin and the myostatin propeptide (1). By amino acid sequence, human GASP-1 is 90% and 55% identical to mouse GASP-1 and human GASP-2, respectively.

• References:

1. Hill, J.J. et al. (2003) Mol. Endo. 17:1144.

2. Trexler, M. et al. (2001) Proc. Natl. Acad. Sci. 98:3705.

3. Nagy, A. et al. (2003) Eur. Jour. Biochem. 270:2101.

4. Trexler, M. et al. (2002) Biol. Chem. 383:223.

• Long Name:

  Growth and Differentiation Factor-associated Serum Protein-1

• Entrez Gene IDs:

  124857 (Human)

• Alternate Names:

  GASP1; GASP-1; Growth and differentiation factor-associated serum protein 1; hGASP-1; WAP, follistatin, immunoglobulin, kunitz and NTR domain-containing-relatedprotein; WAP, follistatin/kazal, immunoglobulin, kunitz and netrin domain containing 2; WAP, FS, Ig, two KU and NTR module related protein; WAP, kazal, immunoglobulin, kunitz and NTR domain-containing protein 2; WFIKKN2; WFIKKN-related protein; WFIKKNRP; WFIKKNRPmultivalent protease inhibitor protein