Recombinant human SPARC protein

SPARC, also known as osteonectin, is a member of secreted matricellular proteins. It is produced by fibroblasts, capillary endothelial cells, platelets and macrophages, especially in areas of tissue morphogenesis and remodeling. This protein regulates cell growth through interactions with the extracellular matrix and cytokines and binds calcium and copper, several types of collagen, albumin, thrombospondin, PDGF and cell membranes. It functions as modulating cell-cell and cell-matrix interactions and its de-adhesive and growth inhibitory properties in non-transformed cell. It is secreted by osteoblasts during bone formation, initiating mineralization and promoting mineral crystal formation. A correlation between SPARC over-expression and ampullary cancers and chronic pancreatitis has been found. It also shows affinity for collagen in addition to bone mineral calcium. Recent studies have also demonstrated a role for SPARC in sensitizing therapy-resistant cancers. Notably, it is linked to human obesity. Recombinant human SPARC, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.