Chapter 12
Molecular Approaches to Understand
Biomineralization of Shell Nacreous Layer
Li-ping Xie, Fang-jie Zhu, Yu-juan Zhou, Chao Yang, and Rong-qing Zhang
Contents
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
12.2 The Structure of the Nacreous Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
12.3 Nacreous Organic Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
12.3.1 Chitin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
12.3.2 Matrix Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
12.4 Function of Matrix Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
12.4.1 Constructing the Organic Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
12.4.2 Controlling the Nucleation and Growth of Crystals . . . . . . . . . . . . . . . . . . . . . . . . . . 342
12.4.3 Calcium Carbonate Polymorph Specificity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
12.4.4 Pearl Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
12.5 The Molecular Mechanism Involved in Nacreous Biomineralization . . . . . . . . . . . . . . . . . 344
12.5.1 The Nucleation and Growth of Aragonite Crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
12.5.2 The Orientation of Crystal Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
12.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Abstract The nacreous layer of molluskan shells, which consists of highly oriented aragonitic crystals and an organic matrix (including chitin and proteins), is a
product of biomineralization. This paper briefly introduces the recent research
advances on nacre biomineralization of shells from bivalves and gastropods,
which mainly focus on analysis of the micro- and nano-structure and components
of shell nacreous layers, and investigations of the characteristics and functions of
matrix proteins from nacre. Matrix proteins not only participate in construction of
the organic nacre framework, but also control the nucleation and growth of aragonitic crystals, as well as determine the polymorph specificity of calcium carbonate
L.-p. Xie (*)
Protein Science Laboratory of the Ministry of Education, Institute of Marine Biotechnology,
School of Life Sciences, Tsinghua University, Beijing 100084, P. R. China
e-mail: lpxie@mail.tsinghua.edu.cn
W.E.G. M€ uller (ed.), Molecular Biomineralization, Progress in Molecular
and Subcellular Biology 52, DOI 10.1007/978-3-642-21230-7_12,
# Springer-Verlag Berlin Heidelberg 2011
331
Molecular Approaches to Understand
Biomineralization of Shell Nacreous Layer
Li-ping Xie, Fang-jie Zhu, Yu-juan Zhou, Chao Yang, and Rong-qing Zhang
Contents
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
12.2 The Structure of the Nacreous Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
12.3 Nacreous Organic Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
12.3.1 Chitin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
12.3.2 Matrix Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
12.4 Function of Matrix Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
12.4.1 Constructing the Organic Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
12.4.2 Controlling the Nucleation and Growth of Crystals . . . . . . . . . . . . . . . . . . . . . . . . . . 342
12.4.3 Calcium Carbonate Polymorph Specificity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
12.4.4 Pearl Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
12.5 The Molecular Mechanism Involved in Nacreous Biomineralization . . . . . . . . . . . . . . . . . 344
12.5.1 The Nucleation and Growth of Aragonite Crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
12.5.2 The Orientation of Crystal Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
12.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Abstract The nacreous layer of molluskan shells, which consists of highly oriented aragonitic crystals and an organic matrix (including chitin and proteins), is a
product of biomineralization. This paper briefly introduces the recent research
advances on nacre biomineralization of shells from bivalves and gastropods,
which mainly focus on analysis of the micro- and nano-structure and components
of shell nacreous layers, and investigations of the characteristics and functions of
matrix proteins from nacre. Matrix proteins not only participate in construction of
the organic nacre framework, but also control the nucleation and growth of aragonitic crystals, as well as determine the polymorph specificity of calcium carbonate
L.-p. Xie (*)
Protein Science Laboratory of the Ministry of Education, Institute of Marine Biotechnology,
School of Life Sciences, Tsinghua University, Beijing 100084, P. R. China
e-mail: lpxie@mail.tsinghua.edu.cn
W.E.G. M€ uller (ed.), Molecular Biomineralization, Progress in Molecular
and Subcellular Biology 52, DOI 10.1007/978-3-642-21230-7_12,
# Springer-Verlag Berlin Heidelberg 2011
331