Characterization of biomineralizing proteins from the proteome of the marine snail haliotis laevigata

The formation of the biogenic composite material nacre is a process of self-assembling and occurs at standard ambient conditions. The highly ordered structure of nacre is composed of approximately 98 wtR0calcium carbonate crystals and less than 2 wtR0organic materials (proteins and polysaccharides). Proteins obviously play a key role in structure formation and regulation of nacre, they guide and control its growth. In this thesis, the biomineralizing proteins from nacre of the marine gastropod Haliotis laevigata were characterized with different techniques. The focus was set on the nacre protein perlucin because this protein was shown to be the major component of the total protein fraction. Furthermore it became evident that most of the biomineralizing proteins are tightly bound to the chitin matrix. A precipitation assay was used to investigate the influence of soluble matrix proteins on CaCO3 precipitation rates. The nacre proteins showed an enormous specific and concentration depending function on CaCO3 precipitation. Using mass spectrometry an overview of the proteome of the shell of Haliotis laevigata could be achieved (without de novo-results)