New discovery paves the way for copper's entrance into MRI contrast agents
A new scientific discovery could pave the way for copper utilization in MRI contrast media agents.
Researchers recently created an abiological copper binding site that binds exclusively to oxygen donor atoms within a protein scaffold; that discovery could have utility in producing MRI contrast with fewer risks than that of traditional gadolinium-based agents—a discovery that contradicts the notion that copper is not suitable for use in contrast media. What’s more, this structure was found to produce greater relaxivity compared to contrast agents currently in use, which could improve image quality while also reducing the potential for adverse effects, according to new research on the matter.
This new discovery is the result of a collaboration between researchers from the Universities of Birmingham and St Andrews, as well as Diamond Light Source. The group published their findings recently in PNAS.
“Despite copper largely being disregarded for use in MRI contrast agents, our binding site was shown to display extremely promising contrast agent capabilities, with relaxivities equal and superior to the Gd(III) agents used routinely in clinical MRI,” study co-author Anna Peacock, reader in bioinorganic chemistry at the University of Birmingham, and colleagues explained. “Our discovery showcases a powerful approach for accessing new tools or agents for imaging applications.”
For their work, the team designed an artificial copper coiled coil to create a binding site within a protein scaffold. In doing so, they were able to expand upon the functional capabilities of copper to realms that have not been achieved before.
“Metal sites that are not part of the repertoire of biology are vital in providing protein designers with an expanded toolbox of chemistries they can use to design new functional systems such as the promising imaging capabilities reported here,” the group noted.
Copper-based imaging agents also could have utility in PET imaging, the team suggested, before acknowledging that more work needs to be done to ensure the stability of the new copper protein site. The group, however, is optimistic about what their discovery means for the future.
“This opens up applications beyond what biology is currently capable of and is the ultimate goal of metalloprotein design, and more generally synthetic biology,” the group concluded. “This work showcases some of the advantages of using simple miniature protein scaffolds as ligands into which to engineer new, and maybe currently unknown, metal-binding sites.”
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