Caspartin and Calprismin, Two Protiens of the Shell Calcitic Prsims of the Mediterranean Fan Mussle Pinna nobilis

Frédéric Marin et al JBC 2005

Two proteins were isolated one is 38-kDA (calprismin) another one is  17kDA(caspartin). Caspartin forms mutlimers and self-aggregates and inhibits the precipitation of calcium carbonate precipitation in vitro. Caspartin is found between the prsims and the surrounding insoluble sheets, this suggests the prominent role of aspartic acid-rich proteins for the building of calcitic prsims among mollusks.