MAGP-2 (Microfibril-associated glycoprotein 2), also called MFAP5 (microfibril associated protein 5) is a secreted, cell-associated 25kD mammalian member of the MFAP family of proteins. Human MAGP-2 cDNA encodes 173aa including a 21aa signal sequence, an RDG motif aa30-32, absent in MAGP-1) and a central cysteine-rich binding domain aa84-140. One potential splice variant shows a 10aa deletion between aa73-82 that includes the only potential glycosylation site. Mature human MAGP-2 shares 80%, 82%, 82%, 84% and 85% aa identity with mouse, rat, bovine, porcine and canine MAGP-2, respectively. Both MAGP-1 and MAGP-2 bind and covalently crosslink fibrillins 1 and 2 through the binding domain, but MAGP-2 has more limited distribution and binds a more limited set of extracellular matrix proteins. However, the MAGP-2 RGD motif binds to the integrin av b3, allowing cell attachment to microfibrils. MAGP-2 is thought to facilitate microfibril assembly and induce elastin fiber formation. Through its binding to EGF repeats, MAGP-2 mediates the metalloproteinase-dependent release of Jagged1 and the metalloproteinase-independent release of Notch extracellular domains. In endothelial cells, MAGP-2 promotes angiogenic sprouting through inhibiting Notch signaling, binding integrin av b3 (which then enhances VEGF signaling), and/or enhancing endothelial cell response to FGF basic and EGF. In ovarian cancer, MAGP-2 expression is associated with cancer cell survival, increased microvessel density, and poor prognosis. Skin MAGP-2 expression is increased in human scleroderma and the tight skin (TSK) mouse, MAGP-2 may contribute to abnormal collagen accumulation in these conditions by increasing the half-life of type I collagen. Fibrillin-1 mutations within the region that binds MAGP-2 can be found in Marfan syndrome. Source: Recombinant corresponding to aa22-173, from human MAGP-2 fused to C-terminal 6-His-tag expressed in mouse myeloma cell line, NSO. Molecular Weight: ~18.1kD Biological Activity: Measured by the ability of the immobilized protein to support the adhesion of BUD-8 human skin fibroblast cells. When 2x104 cells/well are added to Recombinant Human MAGP-2 coated plates (10ug/ml with 100ul/well), ~50-75% will adhere after one hour at 37 C. Endotoxin: ~1EU/1ug (LAL) Storage and Stability: Lyophilized powder may be stored at -20C. Stable for 12 months at -20C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20C. Reconstituted product is stable for 3 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
