Parvalbumin (PARV)

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Parvalbumin (PARV) consists of three EF-hands, the first of which does not bind calcium and covers the (potential) hydrophobic patch of the lobe formed by the C-terminal two domains. The EF-hands are numbered 2, 3, & 4 because they cluster sequentially with EVEN, ODD, EVEN. The first domain is inferred to have been deleted. EF-hands 3 & 4 of PARV have high affinity for calcium and for magnesium. In the resting muscle cell PARV is in the two magnesium form. Following a pulse of messenger calcium the bound Mg2+ ions dissociate slowly and the excess Ca2+ ions are bound by parvalbumin thereby permitting relaxation of skeletal muscle [3]. Whether PARV also performs this relaxing function in other tissues is not known.