Active Bone Sialoprotein (BSP)

Bone Sialoprotein (BSP) is a highly glycosylated and phosphorylated non-collagenous protein that plays a pivotal role in mineralized tissues, particularly in bone and dentin. As a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING) family, it is primarily synthesized by osteoblasts, odontoblasts, and chondrocytes, and is prominently localized in the extracellular matrix of mineralizing tissues. Additionally, it also has the function of cell adhesion. Therefore, we measure the activity of recombinant human BSP by the ability of the immobilized protein to support the adhesion of MCF-7 cell. When 5 x 104 cells/well are added to different concentrations of recombinant human BSP coated plates, cells will adhere after 2 hour incubation at 37 ℃. The adhesion of MCF-7 after 2 hour incubation at 37 ℃ observed by inverted microscope was shown in Figure 1. Cell adherent was in a dose dependent manner, the result was shown in Figure 2, the EC50 was 0.44 μg/ml.