Cloning and Characterization of Four Novel Coral Acid-Rich Proteins that Precipitate Carbonates In Vitro
| Autor: | Ehud Zelzion, Tali Mass, J. Dongun Kim, Jeana L. Drake, Paul G. Falkowski, Debashish Bhattacharya, Liti Haramaty |
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| Rok vydání: | 2013 |
| Předmět: |
0106 biological sciences
Mineralized tissues Molecular Sequence Data Biology Stylophora pistillata engineering.material 010603 evolutionary biology 01 natural sciences General Biochemistry Genetics and Molecular Biology Calcium Carbonate 03 medical and health sciences chemistry.chemical_compound Calcification Physiologic Phylogenetics Extracellular Animals Amino Acid Sequence 14. Life underwater Cloning Molecular Peptide sequence Phylogeny 030304 developmental biology 0303 health sciences Agricultural and Biological Sciences(all) Biochemistry Genetics and Molecular Biology(all) Ecology Aragonite Proteins Anthozoa biology.organism_classification Extracellular Matrix Calcium carbonate Biochemistry chemistry engineering General Agricultural and Biological Sciences Sequence Alignment Biomineralization |
| Zdroj: | Current Biology. 23:1126-1131 |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/j.cub.2013.05.007 |
| Popis: | SummaryBiomineralization is a widely dispersed and highly regulated but poorly understood process by which organisms precipitate minerals from a wide variety of elements [1]. For many years, it has been hypothesized that the biological precipitation of carbonates is catalyzed by and organized on an extracellular organic matrix containing a suite of proteins, lipids, and polysaccharides [2, 3]. The structures of these molecules, their evolutionary history, and the biophysical mechanisms responsible for calcification remain enigmatic. Despite the recognition that mineralized tissues contain proteins that are unusually rich in aspartic and glutamic acids [4–6], the role of these proteins in biomineralization remains elusive [5, 6]. Here we report, for the first time, the identification, cloning, amino acid sequence, and characterization of four highly acidic proteins, derived from expression of genes obtained from the common stony coral, Stylophora pistillata. Each of these four proteins can spontaneously catalyze the precipitation of calcium carbonate in vitro. Our results demonstrate that coral acid-rich proteins (CARPs) not only bind Ca2+ stoichiometrically but also precipitate aragonite in vitro in seawater at pH 8.2 and 7.6, via an electrostatic interaction with protons on bicarbonate anions. Phylogenetic analysis suggests that at least one of the CARPs arose from a gene fusion. Similar, highly acidic proteins appear to have evolved several times independently in metazoans through convergence. Based purely on thermodynamic grounds, the predicted change in surface ocean pH in the next decades would appear to have minimal effect on the capacity of these acid-rich proteins to precipitate carbonates. |
| Databáze: | OpenAIRE |
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