title: Cyanobacterial megamolecule sacran efficiently forms LC gels with very heavy metal ions.
abstract: We extracted the megamolecular polysaccharide sacran, which contains carboxylate and sulfate groups, from the jellylike extracellular matrix (ECM) of the cyanobacterium Aphanothece sacrum, which has mineral adsorption bioactivity. We investigated the gelation properties of sacran binding with various heavy metal ions. The sacran chain adsorbed heavier metal ions such as indium, rare earth metals, and lead ions more efficiently to form gel beads. In addition, trivalent metal ions adsorbed onto the sacran chains more efficiently than did divalent ions. The investigation of the metal ion binding ratio on sacran chains demonstrated that sacran adsorbed gadolinium trivalent ions more efficiently than indium trivalent ions. Gel bead formation may be closely correlated to the liquid-crystalline organization of sacran.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Maiko K
authors.initials: MK
authors.lastname: Okajima
authors.forename: Shinji
authors.initials: S
authors.lastname: Miyazato
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kaneko
mesh_terms: D000327:Adsorption; D000423:Alcian Blue / Q000494:pharmacology; D002853:Chromatography, Liquid / Q000379:methods; D004396:Coloring Agents / Q000494:pharmacology; D000458:Cyanobacteria / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007204:Indium / Q000737:chemistry; D007477:Ions; D007854:Lead; D046911:Macromolecular Substances; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; D005782:Gels; D007477:Ions; D046911:Macromolecular Substances; D008670:Metals; D011134:Polysaccharides; D007204:Indium; D007854:Lead; D000423:Alcian Blue