May be specifically involved in the formation of the nacreous layer. Homooligomer; disulfide-linked. May also be disulfide-linked to insoluble organic matrix. Component of conchiolin, the organic matrix of nacre. Is dispersed in calcium carbonate and also linked by disulfide bonds to the organic core of nacre. According to PubMed:11250534, amino acids 4 and 11 may be sulfated or phosphorylated. By similarity with the N14 matrix protein, amino-acid 4 may be a cysteine involved in a disulfide bond. P.maxima nacre is used in implants to induce in vivo osteogenesis. Belongs to the N16 matrix protein family.