Osteocalcin or bone Gla protein (BGP) is a major non-collagenous protein of the bone matrix. It has a molecular weight of approximately 6000 Dalton and consists in most species of 49 amino acids; however, rat osteocalcin consists of 50 amino acids.
Osteocalcin has a unique property for binding to calcium facilitated by the presence of 2-3 gamma-carboxyglutamic acids at position 17, 21 and 24. The mid-molecular part of osteocalcin, especially the amino acids between 20 and 30, exhibits a high degree of inter-species conservation.
The Rat-MID? Osteocalcin EIA is based upon the competitive binding of a monoclonal antibody to soluble osteocalcin or to immobilised osteocalcin. Briefly, the monoclonal antibody is raised against human osteocalcin and recognizes the mid-molecular part (amino acids 21-29) of the molecule.
