Gamma carboxyglutamic acid (Gla) is a non-proteinogenic amino acid derived from glutamic acid that plays a vital role in various biological processes. It is characterized by the presence of a carboxylic acid group at the gamma position of the glutamic acid molecule. The carboxylation of glutamic acid occurs through a vitamin K-dependent post-translational modification process known as gamma-carboxylation.
The main function of gamma carboxyglutamic acid is to serve as a calcium-binding residue in certain proteins synthesized within the body. The carboxylation process allows these proteins, known as Gla proteins, to bind and interact with calcium ions, thereby facilitating their involvement in blood coagulation, bone mineralization, and vascular calcification. Examples of Gla proteins include clotting factors such as prothrombin and factors VII, IX, and X, as well as various proteins found in bone and teeth.
Gamma carboxyglutamic acid is also implicated in regulating gene expression, cell signaling, and apoptosis. The carboxylation of specific glutamic acid residues within certain regulatory proteins allows them to interact with calcium ions and participate in intracellular signaling pathways. By modulating these pathways, Gla proteins can influence various cellular processes, including cell growth, differentiation, and programmed cell death.
Overall, gamma carboxyglutamic acid is a crucial amino acid that plays a diverse range of roles in biological systems, particularly in processes involving calcium binding, blood clotting, bone formation, and cellular signaling. Its carboxylation is dependent on vitamin K, highlighting the importance of this vitamin in maintaining proper function and health.
