title: Solubilization and chemical characterization of an insoluble matrix protein in the gastroliths of a crayfish, Procambarus clarkii.
abstract: The gastrolith of the crayfish Procambarus clarkii contains a small amount of an organic matrix that is mainly chitin and proteins, together with a large amount of calcium carbonate. As the first step to understand the mechanism of calcification, we tried to characterize matrix proteins in the gastrolith. An insoluble matrix protein, referred to as gastrolith matrix protein, was made soluble with 1% SDS containing 10 mM dithiothreitol, and was purified by reverse-phase high-performance liquid chromatography. The protein had a molecular weight of about 50,500 and a blocked amino terminus. By enzymatic digestion and microsequencing, five partial amino acid sequences with a total of 225 amino acid residues were identified and found to include a repetitive sequence not reported previously.
authors.affiliation: Ocean Research Institute, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: N
authors.initials: N
authors.lastname: Tsutsui
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Yanagisawa
authors.forename: H
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003400:Astacoidea / Q000737:chemistry / Q000502:physiology*; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment; D012995:Solubility
chemical_list: D000596:Amino Acids; D016326:Extracellular Matrix Proteins; D002119:Calcium Carbonate