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The multiple roles of carbonic anhydrase in calcium carbonate mineralization.
- Source :
- CrystEngComm; 12/28/2019, Vol. 21 Issue 48, p7407-7423, 17p
- Publication Year :
- 2019
-
Abstract
- Carbonic anhydrase (CA), a ubiquitous enzyme that catalyzes the reversible hydration of CO<subscript>2</subscript>, is known to be involved in the formation of CaCO<subscript>3</subscript> biominerals and is currently used for biomimetic CO<subscript>2</subscript> mineral sequestration. However, its specific role(s) in calcium carbonate (bio)mineralization is poorly understood. Here we show that CA catalyzes the formation of the reactive precursors (i.e., HCO<subscript>3</subscript><superscript>−</superscript> and CO<subscript>3</subscript><superscript>2−</superscript> ions) required for mineralization, accelerates the precipitation of metastable amorphous calcium carbonates and their solution-mediated conversion into crystalline calcite, which grows via a non-classical nanoparticle aggregation mechanism that facilitates CA occlusion. Ca<superscript>+</superscript> and CO<subscript>3</subscript><superscript>2−</superscript> ions promote the partial unfolding and oligomerization of CA, resulting in fibril- and sheet-like supramolecular assemblies that template nanostructured calcium carbonate crystallization. By losing its catalytic activity following the observed conformational changes, CA elicits a mechanism for arresting calcium carbonate mineralization. Our results show that CA can play multiple, until now unrecognized, critical roles, namely, as an enzyme and structural protein in CaCO<subscript>3</subscript> biomineralization and also helps to explain the observed loss of enzymatic activity during ex situ CO<subscript>2</subscript> mineral sequestration. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14668033
- Volume :
- 21
- Issue :
- 48
- Database :
- Complementary Index
- Journal :
- CrystEngComm
- Publication Type :
- Academic Journal
- Accession number :
- 140273529
- Full Text :
- https://doi.org/10.1039/c9ce01544b