title: Layer-by-Layer Proteomic Analysis of Mytilus galloprovincialis Shell.
abstract: Bivalve shell is a biomineralized tissue with various layers/microstructures and excellent mechanical properties. Shell matrix proteins (SMPs) pervade and envelop the mineral crystals and play essential roles in biomineralization. Despite that Mytilus is an economically important bivalve, only few proteomic studies have been performed for the shell, and current knowledge of the SMP set responsible for different shell layers of Mytilus remains largely patchy. In this study, we observed that Mytilus galloprovincialis shell contained three layers, including nacre, fibrous prism, and myostracum that is involved in shell-muscle attachment. A parallel proteomic analysis was performed for these three layers. By combining LC-MS/MS analysis with Mytilus EST database interrogations, a whole set of 113 proteins was identified, and the distribution of these proteins in different shell layers followed a mosaic pattern. For each layer, about a half of identified proteins are unique and the others are shared by two or all of three layers. This is the first description of the protein set exclusive to nacre, myostracum, and fibrous prism in Mytilus shell. Moreover, most of identified proteins in the present study are novel SMPs, which greatly extended biomineralization-related protein data of Mytilus. These results are useful, on one hand, for understanding the roles of SMPs in the deposition of different shell layers. On the other hand, the identified protein set of myostracum provides candidates for further exploring the mechanism of adductor muscle-shell attachment.
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, China; Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.affiliation: Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liao
authors.affiliation: Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Xin-Xing
authors.initials: XX
authors.lastname: Wang
authors.affiliation: Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Lin-Fei
authors.initials: LF
authors.lastname: Bao
authors.affiliation: Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Fan
authors.affiliation: Biotechnology Center, Chinese Academy of Fishery Science, Beijing, China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Li
authors.affiliation: Laboratory of Marine Biological Protein Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang, China.
authors.forename: Chang-Wen
authors.initials: CW
authors.lastname: Wu
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of Chinese, Qingdao, China.
authors.forename: Shu-Wei
authors.initials: SW
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D060105:Animal Shells / Q000378:metabolism*; D000818:Animals; D008903:Minerals / Q000378:metabolism*; D008969:Molecular Sequence Data; D049878:Mytilus; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D008903:Minerals; D020543:Proteome