Bone gamma-carboxyglutamate protein (Osteocalcin) (BGLAP (osteocalcin, BGP))

Bone gamma-carboxyglutamate protein, commonly referred to as osteocalcin (BGLAP or BGP), is a small (49 amino acid) non-collagenous, vitamin K-dependent protein hormone primarily secreted by osteoblasts in bone and dentin[1][5]. It is involved in bone mineralization through high-affinity calcium ion binding enabled by γ-carboxyglutamic acid residues, whose carboxylation requires vitamin K[1][5]. Osteocalcin in its uncarboxylated form acts as a hormone affecting several organs: stimulating insulin release in the pancreas, sensitizing fat and muscle to insulin, enhancing muscle energy utilization, inducing testosterone synthesis in testes, and influencing neural functions in the brain[1]. Osteocalcin is clinically used as a biomarker for bone formation regulation and for monitoring the effects of osteoporosis therapies, such as those using teriparatide[1][9]. Its synthesis and circulating levels are sensitive to vitamin K status and are reduced by vitamin K antagonists[6]. Osteocalcin and related proteins (such as matrix Gla protein) are essential regulators of biomineralization and overall skeletal health[1][3][6][7].

Other names

OsteocalcinBone Gla proteinBGLAPBGPBone gamma-carboxyglutamic acid-containing protein

Modulation by vitamin K-dependent γ-carboxylation (enabling calcium binding); As a hormone, influences insulin secretion, insulin sensitivity, energy metabolism, and testosterone production[1]; Used as a biomarker for monitoring therapeutic efficacy in bone anabolic treatments[1][9]