Parvalbumin

Parvalbumin (PV) is a calcium-binding protein with low molecular weight (typically 9-11 kDa). In humans, it is encoded by the PVALB gene. It is a member of the albumin family; it is named for its size (parv-, from Latin parvus small) and its ability to coagulate.

It has three EF hand motifs and is structurally related to calmodulin and troponin C. Parvalbumin is found in fast-contracting muscles, where its levels are highest, as well as in the brain and some endocrine tissues.

Parvalbumin is a small, stable protein containing EF-hand type calcium binding sites. It is involved in calcium signaling. Typically, this protein is broken into three domains, domains AB, CD and EF, each individually containing a helix-loop-helix motif. The AB domain houses a two amino-acid deletion in the loop region, whereas domains CD and EF contain the N-terminal and C-terminal, respectively.

Calcium binding proteins like parvalbumin play a role in many physiological processes, namely cell-cycle regulation, second messenger production, muscle contraction, organization of microtubules and phototransduction. Therefore, calcium-binding proteins must distinguish calcium in the presence of high concentrations of other metal ions. The mechanism for the calcium selectivity has been extensively studied.