Identification (Characterization) and Function Studies of Matrix Protein from the Oyster Pinctada fucata

Abstract

Shell matrix protein (SMP) which is extracted from shell and extrapallial fluid matrix protein (EPFMP) which is extracted from extrapallial fluid have important functions in biomineralization during shell formation of Pinctada fucata. In the past decades, the functions of SMPs and EPFMPs were gradually revealed. In 2015, our group identified 72 unique SMPs in Pinctada fucata by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of proteins extracted from the shells of P. fucata aligned with a draft genome. In this chapter, we introduced SMPs from nacreous layer (P14, N40, and PfN23), from prismatic layer (KRMP, KRMP-3, and Prisilkin-39), from both prismatic and nacreous layer (MSI7, PfN44, and PfY2), EPFMP and extracellular matrix protein expressed by mantle (EFCBP and Ferritin). For example, P14 plays a crucial role during nacre biomineralization. N40 could stimulate the nucleation of aragonite drastically by serving as a nucleation site. The basic protein PfN23 might be a key accelerator during the regulation of crystal growth in nacre. KRMP protein family plays important roles in the framework formation of prism.