- nearly 99% of the total body magnesium is located in bone or the intracellular space.
- second plentiful cation of the extracellular fluids.
- mg is a cofactor of all enzymes involved in phosphate transfer reactions utilizing ATP and other nucleotide triphosphates as substrate.
- required for the structural integrity of numerous intracellular proteins and nucleic acids.
- a substrate or cofactor for important enzymes such as adenosine triphosphatase, guanosine triphosphatase, phospholipase C, adenylate cyclase and guanylate cyclase.
- a required cofactor for the activity of over 300 other enzymes.
- a regulator of ion channels ; an important intracellular signaling molecule.
- a modulator of oxidative phosphorylation.
- Mg is chelated between the beta and gamma phosphates, diminishes the dense anionic character of ATP.
- only 1% to 3% of total intracellular Mg exist as a free ionized from.
- total cellular concentration can vary from
- intracellular Mg is predominantly complexed to organic molecules.