Technical Data
Macrophage Stimulating Protein, C672A Mutation, Recombinant, Human (MSP) (BSA Free)
Molecular Biology Storage: -20CShipping: Blue Ice
Macrophage stimulating protein (MSP), also known as HGF-like protein, and scatter factor-2, is a member of the HGF family of growth factors (1). MSP is secreted as an inactive single chain precursor (pro-MSP) that contains a PAN/APPLE-like domain, four kringle domains, and a peptidase S1 domain which lacks enzymatic activity (2). Human MSP shares 79% aa sequence identity with mouse MSP and 44% aa sequence identity with human HGF. Pro-MSP is secreted by hepatocytes under the positive and negative control of CBP in complex with either HNF-4 or RAR, respectively (3). Circulating pro-MSP is proteolytically cleaved in response to tissue injury to yield biologically active disulfide linked heterodimers consisting of a 45-62 kD alpha and a 25-35 kD beta chain (4, 5). Pro-MSP can be activated by MT-SP1, a transmembrane protease that is expressed on macrophages and is upregulated in many cancers (6). Heterodimeric MSP, as well as the isolated beta chain, binds to MSP R/Ron with high-affinity, although only heterodimeric MSP can induce receptor dimerization and signaling (7, 8). MSP induces macrophage and keratinocyte proliferation and osteoclast activation (9, 10). It also inhibits LPS- or IFN-induced iNOS and IL-12 expression by macrophages and prevents apoptosis of epithelial cells separated from the ECM (11, 12). The substitution of cysteine 672 (in the beta chain) with alanine significantly increases the bioactivity of recombinant MSP, apparently by limiting incorrect disulfide bond formation between the alpha and beta chains (13).

Source: A DNA sequence encoding human MSP (Met 1-Gly 711; Accession # AAA59872) with C672A mutation (Wahl, R.C. et al., 1997, J. Biol. Chem. 272:15053-15056) was expressed in Chinese Hamster Ovary cells.

Molecular Mass: The mature recombinant human MSP (C672A) is a disulfide-linked heterodimer consisting of a 465 aa residue -chain (Gln 19-Arg 483) and a 228 aa residue -chain (Val 484-Gly 711) with calculated molecular masses of approximately 53 kD and 25 kD, respectively. As a result of glycosylation, the recombinant human MSP (C672A) migrates at 85 kD in SDS-PAGE under non-reducing conditions and the and -chains migrate as 60 kD and 30 kD proteins, respectively, under reducing conditions.

Endotoxin: < 1.0 EU per 1 g of the cytokine as determined by the LAL method. Endotoxin Level

Activity: Measured by its ability to activate MSP R/Ron in a human breast cancer cell line, MDA-MB-453. 80 ng/mL of the rhMSP (C672A) significantly induces phosphorylation of MSP R/Ron measured by DuoSet IC human phopho-MSP R/Ron kit.

Reconstitution: It is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long termstorage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial.

Storage and Stability: Lyophilized samples are stable for up to twelve months at -20C. Upon reconstitution, this protein, in the presence of a carrier protein, can be stored under sterile conditions at 2-8 C for one month or at -20C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.
Source: Chinese Hamster Ovary (CHO) cells
Purity: 95, as determined by SDS-PAGE and visualized by silver stain.
Concentration: As reported
Form: Supplied as a lyophilized powder in PBS.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
1. Wang, M.-H. et al., 2002, Scand. J. Immunol.56:545.
2. Han, S. et al., 1991, Biochemistry 30:9768.
3. Muraoka, R.S. et al., 1999, Endocrinology 140:187.
4. Wang, M.-H. et al., 1996, J. Clin. Invest. 97:720.
5. Nanney, L.B. et al., 1998, J. Invest. Dermatol. 111:573.
6. Bhatt, A.S. et al., 2007, Proc. Natl. Acad. Sci. 104:5771.
7. Wang, M.-H. et al., 1997, J. Biol. Chem. 272:16999.
8. Danilkovitch, A. et al., 1999, J. Biol. Chem. 274:29937.
9. Wang, M.-H. et al., 1996, Exp. Cell Res. 226:39.
10. Kurihara, N. et al., 1998, Exp. Hematol. 26:1080.
11. Morrison, A.C. et al., 2004, J. Immunol. 172:1825.
12. Liu, Q.P. et al., 1999, J. Immunol. 163:6606.
13. Wahl, R.C. et al., 1997, J. Biol. Chem. 272:15053.

Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.