On Biomineralization: Enzymes Switch on Mesocrystal Assembly

Ashit Rao, Teresa Roncal-Herrero, Elina Schmid, Markus Drechsler, Martin Scheffner, Denis Gebauer, Roland Kröger, Helmut Cölfen*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Cellular machineries guide the bottom-up pathways toward crystal superstructures based on the transport of inorganic precursors and their precise integration with organic frameworks. The biosynthesis of mesocrystalline spines entails concerted interactions between biomolecules and inorganic precursors; however, the bioinorganic interactions and interfaces that regulate material form and growth as well as the selective emergence of structural complexity in the form of nanostructured crystals are not clear. By investigating mineral nucleation under the regulation of recombinant proteins, we show that SpSM50, a matrix protein of the sea urchin spine, stabilizes mineral precursors via vesicle-confinement, a function conferred by a low-complexity, disordered region. Site-specific proteolysis of this domain by a collagenase initiates phase transformation of the confined mineral phase. The residual C-type lectin domain molds the fluidic mineral precursor into hierarchical mesocrystals identical to structural crystal modules constituting the biogenic mineral. Thus, the regulatory functions of proteolytic enzymes can guide biomacromolecular domain constitutions and interfaces, in turn determining inorganic phase transformations toward hybrid materials as well as integrating organic and inorganic components across hierarchical length scales. Bearing striking resemblance to biogenic mineralization, these hybrid materials recruit bioinorganic interactions which elegantly intertwine nucleation and crystallization phenomena with biomolecular structural dynamics, hence elucidating a long-sought key of how nature can orchestrate complex biomineralization processes.
Original languageEnglish
Pages (from-to)357-364
Number of pages8
JournalACS Central Science
Volume5
Issue number2
Early online date1 Feb 2019
DOIs
Publication statusPublished - 27 Feb 2019

Bibliographical note

© 2019 American Chemical Society.

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