• 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 rhBMP-4-induced alkaline phosphatase production by ATDC5 mouse chondrogenic cells. Binnerts, M.E.     et al. (2004) Biochem. Biophys. Res. Commun.     315:272. The ED    ₅₀ for this effect is 0.5-2 µg/mL in the presence of 30 ng/mL of Recombinant Human BMP-4 (Catalog # ).

• Source

  Mouse myeloma cell line, NS0-derived Val34-Asp369, with an N-terminal 7-His tag & Ala39-Asp369 (N-terminal fragments) & Pro370-Arg685 (C-terminal fragment)

• Accession #

• N-terminal Sequence    
  Analysis

  His & Ala39 (N-terminal fragments) & Pro370 (C-terminal fragment)

• Structure / Form

  Disulfide-linked heterodimer

• SDS-PAGE

  50-55 kDa doublet and 39 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: Crossveinless-2/CV-2

Crossveinless-2 (CV-2), also known as bone morphogenetic protein-binding endothelial cell precursor-derived regulator (BMPER), is a secreted chordin-like protein that modulates the BMP signaling pathway (1 - 3). Human CV-2 is synthesized as a 685 amino acid (aa) residue precursor protein with a putative 39 aa signal peptide, five tandem chordin-like cysteine-rich (CR) domains, a partial von Willebrand factor type D domain (vWD), and a carboxyl trypsin inhibitor-like cysteine-rich domain (TIL) (1, 4). Secreted CV-2 is reported to be proteolytically cleaved to generate two fragments that are disulfide-linked (1, 2). The cleavage site of R&D Systems’ recombinant CV-2 is found to be between asp³⁶⁹ and pro³⁷⁰ in the GDPH sequence within the vWD domain. This cleavage is likely due to an autocatalytic mechanism triggered by low pH comparable to that of the late secretory pathway (5). The GDPH sequence is conserved in CV-2 from other species. It is also found in multiple proteins that undergo a similar type of cleavage (5). Human CV-2 message is detected in many tissues, with the highest expression detected in adult brain and adult and fetal lung (1). It is also expressed in flk-1⁺ endothelial cell precursors and in primary chondrocytes (2). During embryonic development, CV-2 is expressed in regions of high BMP signaling, such as the posterior primitive streak and the ventral tail bud (4). Human CV-2 shares 92% and 34% aa sequence identity with the mouse and Drosophila homologs, respectively (1, 4). Results from biochemical experiments using recombinant CV-2 show that CV-2 directly interacts with BMP-2, -4, and -6 to antagonize BMP signaling, which can regulate a wide range of differentiation processes (1, 2). In contrast, genetic data from Drosophila suggest that CV-2 potentiates BMP-signaling (6). It is possible that like TSG, CV-2 can positively and negatively modulate BMP signal transduction depending on the cell context (7).

• References:

1. Binnerts, M.E. et al. (2004) Biochem Biophys Res Commun. 315:272.

2. Moser, M. et al. (2003) Mol Cell Biol. 23:5664. 

3. Garcia-Abreu, J. et al. (2002) Gene, 287: 39. 

4. Coffinier, C. et al. (2002) Mech Dev. 119:S179.

5. Lidell, M.E. et al. (2003) J. Biol. Chem. 278:13944.

6. Conley, C.A. et al. (2000) Development 127:3947.

7. Kamimura, M. et al. (2004) Developmental Dynamics 230:434.

• Long Name:

  BMP-binding Endothelial Regulator Protein

• Entrez Gene IDs:

  168667 (Human); 73230 (Mouse)

• Alternate Names:

  BMP binding endothelial regulator; BMP-binding endothelial regulator precursor protein; BMP-binding endothelial regulator protein; BMPER; Bone morphogenetic protein-binding endothelial cell precursor-derived regulator; CRIM3; crossveinless 2; Crossveinless-2; CV2; CV-2; hCV2; KIAA1965; Protein crossveinless-2