Amyloid Assembly Endows Gad m 1 with Biomineralization Properties

• Published in: Biomolecules
• Main Authors: Milagros Castellanos, Almudena Torres-Pardo, Rosa Rodríguez-Pérez, María Gasset
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2018
• Subjects: amyloids; Gad m 1; EF-hand motif; calcium carbonate precipitation; calcite; Microbiology; QR1-502; atlantic cod
• Online Access: https://doi.org/10.3390/biom8010013; https://doaj.org/article/cd7df13ec9a9429c80ea95446eebee67

Acid proteins capable of nucleating Ca2+ and displaying aggregation capacity play key roles in the formation of calcium carbonate biominerals. The helix-loop helix EF-hands are the most common Ca2+-binding motifs in proteins. Calcium is bound by the loop region. These motifs are found in many proteins that are regulated by calcium. Gad m 1, an Atlantic cod β-parvalbumin isoform, is a monomeric EF-hand protein that acts as a Ca2+ buffer in fish muscle; the neutral and acid apo-forms of this protein can form amyloids. Since Ca2+-nucleating proteins have a propensity to form extended β-strand structures, we wondered whether amyloid assemblies of an EF-hand protein were able to influence calcium carbonate crystallization in vitro. Here, we used the Gad m 1 chain as a model to generate monomeric and amyloid assemblies and to analyze their effect on calcite formation in vitro. We found that only amyloid assemblies alter calcite morphology.