Calciumbindende

Calciumbindende is a term used in several Germanic languages (literally "calcium-binding") to describe molecules, proteins or chemical agents that bind calcium ions (Ca2+). In biological contexts it commonly refers to calcium-binding proteins that interact with Ca2+ to regulate cellular processes, to stabilize structures or to mediate signaling. Representative examples include calmodulin, troponin C, parvalbumin, members of the S100 family, annexins and calbindins; many of these contain characteristic EF-hand or other metal-binding motifs.

Functionally, calciumbindende proteins convert changes in intracellular calcium concentration into biochemical responses such as enzyme activation, muscle contraction, neurotransmitter release and gene regulation. In mineralized tissues, calcium-binding matrix proteins (for example osteocalcin) influence hydroxyapatite formation and bone mineralization. Small-molecule calcium chelators and synthetic ligands are also described as calciumbindende when used to sequester Ca2+ in laboratory, industrial or medical settings.

Measurement of calcium binding employs biochemical and biophysical techniques including equilibrium dialysis, isothermal titration calorimetry, spectroscopic probes and fluorescent calcium indicators. Clinically, alterations in expression or function of calcium-binding proteins are associated with neurological disorders, cardiac disease and certain cancers, and calcium-binding reagents are important tools in diagnostics and research. The term is descriptive rather than taxonomic and appears primarily in technical literature and compound descriptions.