About Calcium-Binding Protein:
Calcium is one key element that's important for intracellular signaling, and it regulates several aspects of cell physiology. The EF-hand, with a helix-loop-helix structure, is one of the common calcium-binding motifs. Generally, Calcium-Binding Proteins (CaBP) play significant roles in homeostatic calcium processes. Besides buffering, they may also perform neuroprotective functions. Changes in intracellular calcium irons (Ca2+) are essential to neurotransmission, and they’re also involved in many cellular activities.
Calcium-Binding Protein Function
Biochemical and immunocytochemical research studies have shown that CaBPs exist in the retina. It's thought that the calcium-binding protein revoverin mediates photoreceptor light adaptation events.
However, the function of calmodulin isn't well-established. While biochemical measurements show that it also exists in photoreceptors, immunocytochemical studies (used to closely observe proteins) are yet to back that finding.
From one perspective, calmodulin helps regulate specific enzyme reactions in a calcium-based manner. Apart from controlling effector molecules, this binding protein and several others may act as buffers to calcium. The buffering activities can protect cells from the cytotoxic effects of high calcium concentration.
Calcium Binding Proteins Structure
The most prevalent and highly researched CaBPs are those that bear EF-hand domains such as parvalbumin, S-100 proteins, calcineurin, and calmodulin. Calcium Binding Proteins with ordered structures that lack EF-hand usually include proteins with C2 domain, epidermal growth factor domain, and GLA proteins, among others.
As a universal calcium sensor, calmodulin regulates numerous cellular pathways. While Calmodulin itself is well-structured, it frequently binds to disordered proteins. Intrinsically disordered proteins do not have a 3D structure.