title: A novel highly acidic polysaccharide with inhibitory activity on calcification from the calcified scale "coccolith" of a coccolithophorid alga, Pleurochrysis haptonemofera.
abstract: Coccolith, a calcified scale with species-specific fine structure produced by marine unicellular coccolithophorid algae, consists of calcium carbonate (CaCO(3)) crystals and a small amount of organic matrices. A novel polysaccharide named coccolith matrix acidic polysaccharide (CMAP) was isolated from the coccolith of a coccolithophorid alga, Pleurochrysis haptonemofera. The structure of CMAP was determined by chemical analysis and NMR spectroscopy including COSY, TOCSY, HMQC, and HMBC to be a polysaccharide composed of the following unit: -->4) l-iduronic acid (alpha1-->2) meso-tartaric acid (3-->1) glyoxylic acid (1-->. It has four carboxyl groups per a disaccharide unit as observed in another polysaccharide PS-2 characterized previously in Pleurochrysis carterae. CMAP showed a strong inhibitory activity on CaCO(3) precipitation. These results suggest that CMAP serves as a regulator in the calcification of the coccolith.
authors.affiliation: Department of Functional Bioscience, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ozaki
authors.forename: Shohei
authors.initials: S
authors.lastname: Sakuda
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D056890:Eukaryota / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D011134:Polysaccharides; D002119:Calcium Carbonate