title: Recombinant production of a shell matrix protein in Escherichia coli and its application to the biomimetic synthesis of spherulitic calcite crystals.
abstract: OBJECTIVE
  To overcome the limited production capability of shell matrix proteins and efficiently conduct in vitro CaCO3 biomineralization studies, a putative recombinant shell matrix protein was prepared and characterized.
  
  
  RESULTS
  A glycine-rich protein (GRP_BA) was found in Pinctada fucata as a putative shell matrix protein (NCBI reference sequence; BAA20465). It was genetically redesigned for the production in Escherichia coli. The recombinant protein was obtained in a 400 ml shake-flask culture at approx. 30 mg l(-1) with a purity of >95 %. It efficiently formed a complex with Ca(2+). Ca(2+)-induced agglomeration was like other calcification-related proteins. Spherulitic calcite micro-particles, 20-30 µm diam. with rosette- and sphere-like structures were synthesized in the presence of the recombinant shell protein, which could be formed by stacking and/or aggregation of calcite nanograins and the bound protein.
  
  
  CONCLUSIONS
  Recombinant production of a shell matrix protein could overcome potential difficulties associated with the limited amount of protein available for biomineralization studies and provide opportunities to fabricate biominerals in practical aspects.
authors.affiliation: Department of Chemical Engineering and Applied Science, Chungnam National University, 99 Daehak-ro (St), Yuseong-Gu, Daejeon, 305-764, Korea.
authors.forename: Wooho
authors.initials: W
authors.lastname: Song
authors.affiliation: School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
authors.forename: So Yeong
authors.initials: SY
authors.lastname: Bahn
authors.affiliation: School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.|Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
authors.affiliation: Department of Biotechnology and Bioinformatics, Korea University, 2511 Sejong-ro, Sejong, 339-700, Korea. spack@korea.ac.kr.
authors.forename: Seung Pil
authors.initials: SP
authors.lastname: Pack
authors.affiliation: Department of Chemical Engineering and Applied Science, Chungnam National University, 99 Daehak-ro (St), Yuseong-Gu, Daejeon, 305-764, Korea. biochoi@cnu.ac.kr.
authors.forename: Yoo Seong
authors.initials: YS
authors.lastname: Choi
mesh_terms: D000818:Animals; D032701:Biomimetics; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D049911:Pinctada / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D016326:Extracellular Matrix Proteins; D011994:Recombinant Proteins; D002119:Calcium Carbonate
keywords: Biomineralization; Calcium carbonate; Pearl oyster; Recombinant protein; Spherulitic calcite crystal