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Disordered Conformation with Low P ii Helix in Phosphoproteins Orchestrates Biomimetic Apatite Formation
Author(s) -
Sarem Melika,
Lüdeke Steffen,
Thomann Ralf,
Salavei Pavel,
Zou Zhaoyong,
Habraken Wouter,
Masic Admir,
Shastri V. Prasad
Publication year - 2017
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201701629
Subject(s) - phosvitin , phosphoprotein , circular dichroism , biomineralization , apatite , biophysics , amorphous calcium phosphate , protein secondary structure , calcium , crystallography , materials science , chemistry , phosphorylation , phosphate , biochemistry , chemical engineering , biology , mineralogy , organic chemistry , engineering , protein kinase a
The interplay between noncollagenous proteins and biomineralization is widely accepted, yet the contribution of their secondary structure in mineral formation remains to be clarified. This study demonstrates a role for phosvitin, an intrinsically disordered phosphoprotein, in chick embryo skeletal development, and using circular dichroism and matrix least‐squares Henderson–Hasselbalch global fitting, unravels three distinct pH‐dependent secondary structures in phosvitin. By sequestering phosvitin on a biomimetic 3D insoluble cationic framework at defined pHs, access is gained to phosvitin in various conformational states. Induction of biomimetic mineralization at near physiological conditions reveals that a disordered secondary structure with a low content of P II helix is remarkably efficient at promoting calcium adsorption, and results in the formation of biomimetic hydroxyapatite through an amorphous calcium phosphate precursor. By extending this finding to phosphorylated full‐length human recombinant dentin matrix protein‐1 (17‐513 AA), this bioinspired approach provides compelling evidence for the role of a disordered secondary structure in phosphoproteins in bone‐like apatite formation.