Identification and functional analyses of organic matrices regulating morphology and defect in calcium carbonate crystals of mollusk shells

2015 Fiscal Year Final Research Report

• Project/Area Number: 25850078
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bioorganic chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: Suzuki Michio 東京大学, 農学生命科学研究科, 講師 (10647655)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: バイオミネラル / 炭酸カルシウム / アコヤガイ / モノアラガイ / 酸性ペプチド / キチナーゼ

Outline of Final Research Achievements

Biominerals are biogenic mineralized tissues containing not only inorganic compounds, but also a small amount of organic matrices that play an important role in biomineral formation. The mollusk shells which are typical biominerals consisting of calcium carbonate and organic matrices, have various microstructures.
We identified a novel, small acidic peptide, named ligament intra-crystalline peptide (LICP), from the aragonite crystal of the hinge ligament of Pinctada fucata. We revealed that LICP inhibited the growth of aragonite crystal to stop elongation in the c-axis direction and make the thin fiber of aragonite crystals in the ligament. On the other hand, we showed the chitinase activity from the extract of the shell from fresh water snail, Lymnaea stagnalis. Chitinases degraded the inner side of the shell to reconstruct the shell shape.
In this study, we revealed some important organic matrices to form the fine microstructure of the mollusk shells.

Free Research Field

バイオミネラリゼーション、生物無機化学、生物有機化学、分析化学