ヒトCalbindin Dを定量するキット Human Calbindin D Quantikine ELISA Kit

Calbindin D is a 28-30 kDa member of the Vitamin D-dependent calcium-binding proteins family that also includes Parvalbumin, Calmodulin, S100 Protein G, and Troponin C. It contains six EF hand domains of which four are active calcium binding domains. Calbindin shows 98% amino acid sequence identity with both mouse and rat Calbindin D. EF hand calcium binding proteins are subdivided into two groups, calcium buffers and calcium sensors. Calbindin D is unusual in that it functions as both. As a calcium buffer, Calbindin D is involved in selective reabsorption of Ca2+ in the kidney and the intestine as well as regulating the release of insulin in islet cells of the pancreas. In the brain, Calbindin D is essential in neural function, altering synaptic interactions in the hippocampus and modulating calcium-channel activity and neuronal firing. However, unlike traditional calcium sensors, Calbindin D can bind target proteins such as IMPase or RanBPM in both its apo and Ca2+-loaded states. Calbindin D also interacts directly with Caspase-3 and inhibits the apoptosis of neuronal cells, osteocytes, and osteoblasts. This interaction is specific among Ca2+-binding proteins and requires conformational changes of Calbindin D induced by its Ca2+ binding. Calbindin D depletion in mice suggests that it participates in the pathogenesis of Alzheimer’s Disease by exacerbating neuronal and synaptic loss, apoptotic cell death, and mitochondrial dysfunction. Calbindin D is also expressed in renal distal tubule epithelium, and its levels in the urine can be elevated following kidney damage.