Abstract
Mollusk shells, especially the nacre, are of commercial interest as well as palaeoenvironmental proxies. They are also investigated as biomaterials for medical purposes and biomimetics. Although the mineralogy is well-known and unique (aragonite tablets), the organic components are various. However, determination of the precise composition of the soluble organic matrix (SOM) of the nacreous layer is difficult. Among the range of possible techniques, 1D electrophoresis and High-performance liquid chromatography (HPLC) have previously been applied separately to differentiate pI and molecular weights. To date, no clear correlation has been established between the two parameters obtained in such conditions. Here, we report the use of preparative electrophoresis, coupled with HPLC, to determine the molecular weights of the pI fractions. The results are compared with 2D gel electrophoresis. It is shown that both methods have drawbacks and advantages, and are not redundant. The complexity of the composition of the nacreous tablet shown by scanning electron microscope (SEM) and Atomic Force Microscope (AFM) observations is also evidenced by electrophoresis and HPLC.
Highlights
Mollusk shells are collected for their beautiful shapes and colors
The thin outer shell layer is composed of calcitic prisms, while the thick inner layer is built by aragonitic nacreous tablets
The nacreous tablets are arranged in regular layers (Figure 1g) described as “bricks and mortar”, because tablets are separated by organic lamellae
Summary
Mollusk shells are collected for their beautiful shapes and colors. Ornamentation and color are the main criteria used for taxonomy and phylogeny. Boggild [1] and Taylor et al [2]. Have shown that the mineralogy and the arrangement of the shell layers (microstructure) are related to taxonomy. Detailed works have confirmed the potential use of microstructures for taxonomy and phylogeny [3,4]. Among the various layers known in mollusk shells, some have complex 3D arrangements (crossed lamellar layers), whereas others are simple (prism, nacre). Despite the crossed lamellar layer in the more abundant layer, the nacre is the better-known layer. Are the brick and wall structure easy to decipher, but nacre is used in jewelry and pearl farming
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
