title: Structure and function of matrix proteins and peptides in the biomineral formation in crustaceans.
abstract: Crustaceans have hard cuticle with layered structure, which is composed mainly of chitin, proteins, and calcium carbonate. Crustaceans grow by shedding the old cuticle and replacing it with a new one. Decalcification in the cuticle during the pre-molt stage and concomitant calcification in the stomach to form gastroliths observed in some crustacean species are triggered by the molting hormone. Various proteins and peptides have been identified from calcified cuticle and gastroliths, and their functions have been examined in terms of calcification and interaction with chitin. Acidic nature of matrix proteins is important for recruitment of calcium ions and interaction with calcium carbonate. Examination of the relationship between amino acid sequence containing acidic amino acid residues and calcification inhibitory activity revealed that the potency did not depend on the sequence but on the number of acidic amino acid residues. Calcium carbonate in the calcified tissues of crustaceans is amorphous in many cases. Crustaceans take a strategy to induce and maintain amorphous calcium carbonate by using low-molecular-weight phosphorus compounds.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657, Japan, anagahi@mail.ecc.u-tokyo.ac.jp.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000737:chemistry; D003445:Crustacea / Q000378:metabolism; D018978:Molting; D010455:Peptides / Q000378:metabolism; D011506:Proteins
chemical_list: D010455:Peptides; D011506:Proteins; D002119:Calcium Carbonate