Purification and Structural Characterization of a Novel Class of Protein- Based Magnetic Resonance Imaging Contrast Agents

• Main Author: Hubbard, Kendra Lynette
• Format: Others
• Published: Digital Archive @ GSU 2010
• Subjects: Relaxivity; Magnetic resonance imaging; Contrast agents; Gadolinium; Circular dichroism; Fluorescence resonance energy transfer
• Online Access: http://digitalarchive.gsu.edu/chemistry_theses/33; http://digitalarchive.gsu.edu/cgi/viewcontent.cgi?article=1032&context=chemistry_theses

More than one-third of all Magnetic Resonance Imaging (MRI) scans employ image-enhancing contrast agents to increase the differential signal intensity between diseased and normal tissue. Because current clinical contrast agents exhibit low relaxivity (mM-1 s-1), low dose efficiency, and rapid secretion, we have designed a group of protein-based MRI contrast agents with multiple gadolinium binding sites. In this study, the developed purification method for Class ProCA-3 agents allows for a quick and cost-effective way to abstract up to 109 mg of pure, soluble protein from a 1L E. Coli cell pellet devoid of DNA or RNA “contamination” for extensive animal studies. Circular dichroism far-UV spectra ensure the metal stability of the agents, revealing maintenance of their native α-helical structure in the presence and absence of metal ions. Furthermore, substantial evidence supports the high dose efficiency of these agents, exhibiting up to five folds higher relaxivity than their analogous commercial competitors.