title: Characterization of a matrix protein in the gastroliths of the crayfish Procambarus clarkii.
abstract: As a first step in understanding the calcification mechanism, a matrix protein in the gastrolith of the crayfish Procambarus clarkii was purified and sequenced. The protein was insoluble in acid, but after trypsin digestion, it dissolved in 6 M urea. The trypsin-digested protein dissolved in urea solution was purified by reversed-phase HPLC and designated gastrolith matrix protein fragment. The fragment had a molecular weight of 9658 and a blocked amino terminus. It had tandemly repeated units not reported before at the central part of the sequence, with each unit being Gly-Ser-X1-X2-Phe as the most typical sequence. This peptide was found associated with chitin, a main component of the organic matrix.
authors.affiliation: Ocean Research Institute, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Yanagisawa
authors.forename: H
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea / Q000737:chemistry* / Q000502:physiology; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000032:analysis*; D002137:Calculi / Q000737:chemistry*; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis
chemical_list: D016326:Extracellular Matrix Proteins; D010446:Peptide Fragments; D002119:Calcium Carbonate