title: Mineral proximity influences mechanical response of proteins in biological mineral-protein hybrid systems.
abstract: The organic phase of nacre, which is composed primarily of proteins, has an extremely high elastic modulus as compared to that of bulk proteins, and also undergoes large deformation before failure. One reason for this unusually high modulus could be the mineral-organic interactions. In this work, we elucidate the specific role of mineral proximity on the structural response of proteins in biological structural composites such as nacre through molecular modeling. The "glycine-serine" domain of a nacre protein Lustrin A has been used as a model system. It is found that the amount of work needed to unfold is significantly higher when the GS domain is pulled in the proximity of aragonite. These results indicate that the proximity of aragonite has a significant effect on the unfolding mechanisms of proteins when pulled. These results will provide very useful information in designing synthetic biocomposites, as well as further our understanding of mechanical response in structural composites in nature.
authors.affiliation: Department of Civil Engineering, North Dakota State University, Fargo, North Dakota 58105, USA.
authors.forename: Pijush
authors.initials: P
authors.lastname: Ghosh
authors.forename: Dinesh R
authors.initials: DR
authors.lastname: Katti
authors.forename: Kalpana S
authors.initials: KS
authors.lastname: Katti
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry; D006860:Hydrogen Bonding; D046911:Macromolecular Substances / Q000737:chemistry; D008903:Minerals / Q000737:chemistry*; D008968:Molecular Conformation; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D012694:Serine / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D001704:Biopolymers; D016326:Extracellular Matrix Proteins; D046911:Macromolecular Substances; D008903:Minerals; D011506:Proteins; C109744:lustrin A; D014867:Water; D012694:Serine; D002119:Calcium Carbonate; D005998:Glycine