Surface Coating Rescues Proteins from Magnetite Nanoparticle Induced Damage

Abstract

The presence of magnetic nanoparticles (NPs) in physiological systems induces toxicity through its effects on mitochondrial function and reactive oxygen species (ROS) imbalance. Magnetic NP induced cytotoxicity has been elaborately evaluated for impending threats, however, a detailed investigation is lacking. It is shown that the interaction of Fe3O4 NPs with cytochrome c can lead to different events based on the NPs to protein ratio, the solution conditions, and the type of surface protection. At low NPs concentration, rapid binding and subsequent electron transfer are the preferred events while at higher concentration slow oxidative modification of the protein is initiated. The slow event of protein modification yields conformational disorientation, loss of stability, and formation of amyloid‐like structures with cytochrome c. The possibility that the NP induced oxidative stress and age can work in concert to compromise different aspects of cellular quality control processes is discussed. Suitable surface modifications of the NPs inhibit their direct binding to the protein molecules and minimize NP induced toxicity.

Study of binding interactions between MPT63 protein and Au nanocluster

“…[1][2][3][4][5][6][7] These interactions may alter protein conformation, expose novel epitopes at the protein surface, or perturb the normal protein function inducing unexpected biological reactions and toxicity. 2,[8][9][10][11] The structural changes due to binding of protein on the surface of nanoparticles have been monitored usually by infrared spectroscopy, circular dichroism, uorescence, and NMR. 6,8,12,13 Surface energy transfer (SET) has been used to understand the change of conformation of a protein and its binding site of protein molecules.…”

Earthicle and Its Discontents: A Historical Critical Review of Iron (Oxide) Particles Singly and Doubly Shelled with Silica and/or Carbon

“…The same rationale explains how come only in 2004 were silica-encapsulated iron oxide nanoparticles first considered for use as MRI contrast agents . In spite of this, there were studies demonstrating the rescue of cells from the damage mediated by reactive oxygen species by coating iron oxide nanoparticles with silica . In 2010, coating cubically shaped iron nanoparticles with silica resulted in a material with significant microwave absorption, i.e., the reflection loss exceeding −12 dB in the frequency range of 8–14 GHz for the absorber thickness of 2 mm .…”

“…134 In spite of this, there were studies demonstrating the rescue of cells from the damage mediated by reactive oxygen species by coating iron oxide nanoparticles with silica. 135 In 2010, coating cubically shaped iron nanoparticles with silica resulted in a material with significant microwave absorption, i.e., the reflection loss exceeding −12 dB in the frequency range of 8−14 GHz for the absorber thickness of 2 mm. 136 A study carried out four years later, in 2014, improved this efficacy of lowering the permittivity of the core and attenuating microwaves and reported the reflection loss value of −54 dB at 3.2 GHz for the thickness of 3 mm.…”

Nanoparticle Induced Conformational Switch Between α-Helix and β-Sheet Attenuates Immunogenic Response of MPT63

“…Another report has shown that functionalization of iron oxide NPs with HSA protein is useful for thermal therapy . Recent research in our lab has shown that the interaction between magnetic NPs with a protein can depend on several factors including the concentrations ratio of protein and NPs and solution conditions. , …”

“…25 Recent research in our lab has shown that the interaction between magnetic NPs with a protein can depend on several factors including the concentrations ratio of protein and NPs and solution conditions. 26,27 We show that the binding of arginine coated Fe 3 O 4 NPs (Fe 3 O 4 @Arg NPs) to the wild type (WT) MPT63 triggers a local conformational switch from β-sheet to α-helix, which is associated with partial unfolding. We find that the activity of MPT63 in the nanoconjugated form is reduced significantly, which could be restored by carefully using protein engineering to increase the flexibility of the sequence stretch between 19th and 30th amino acids.…”