Purification of SPARC/osteonectin

Abstract

SPARC is a matricellular protein that regulates cell adhesion, extracelluolar matrix production, growth factor activity and cell cycle. This unit describes the purification of SPARC, also termed osteonectin and BM/40, from cultured mammalian cells. Additional information is presented on the purification of recombinant SPARC (rSPARC) from E. coli and from Sf9 cells, as well as its isolation from blood platelets. Assays for the activity of SPARC, de-adhesion and inhibition of cellular proliferation in vitro, are described. The expression of SPARC during remodeling and repair tissue in response to injury identifies it as a therapeutic target for the treatment of fibrotic disease, certain cancers and other disorders in which regulation of angiogenesis is a key factor.