Jody L Major1, Rene M Boiteau, Thomas J Meade. 1. Department of Chemistry, Biochemistry and Molecular Cell Biology, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA.
Abstract
We report on the mechanism of a series of Zn (II)-activated magnetic resonance contrast agents that modulate the access of water to a paramagnetic Gd (III) ion to create an increase in relaxivity upon binding of Zn (II). In the absence and presence of Zn (II), the coordination at the Gd (III) center is modulated by appended Zn (II) binding groups. These groups were systematically varied to optimize the change in coordination upon Zn (II) binding. We observe that at least one appended aminoacetate must be present as a coordinating group to bind Gd (III) and effectively inhibit access of water. At least two binding groups are required to efficiently bind Zn (II), creating an unsaturated complex and allowing access of water. (13)C isotopic labeling of the acetate binding groups for NMR spectroscopy provides evidence of a change in the metal coordination of these groups upon the addition of Zn (II) supporting our proposed mechanism of activation as presented.
We report on the mechanism of a series of Zn (II)-activated magnetic resonance contrast agents that modulate the access of n class="Chemical">water to a paramagnetic Gd (III) ion to create an increase in relaxivity upon binding of Zn (II). In the absence and presence of Zn (II), the coordination at the Gd (III) center is modulated by appended Zn (II) binding groups. These groups were systematically varied to optimize the change in coordination upon Zn (II) binding. We observe that at least one appended aminoacetate must be present as a coordinating group to bind Gd (III) and effectively inhibit access of water. At least two binding groups are required to efficiently bind Zn (II), creating an unsaturated complex and allowing access of water. (13)C isotopic labeling of the acetate binding groups for NMR spectroscopy provides evidence of a change in the metal coordination of these groups upon the addition of Zn (II) supporting our proposed mechanism of activation as presented.
Authors: A Y Louie; M M Hüber; E T Ahrens; U Rothbächer; R Moats; R E Jacobs; S E Fraser; T J Meade Journal: Nat Biotechnol Date: 2000-03 Impact factor: 54.908
Authors: Lauren M Urbanczyk-Pearson; Frank J Femia; Jeffrey Smith; Giacomo Parigi; Joseph A Duimstra; Amanda L Eckermann; Claudio Luchinat; Thomas J Meade Journal: Inorg Chem Date: 2007-12-12 Impact factor: 5.165
Authors: André F Martins; Veronica Clavijo Jordan; Filip Bochner; Sara Chirayil; Namini Paranawithana; Shanrong Zhang; Su-Tang Lo; Xiaodong Wen; Piyu Zhao; Michal Neeman; A Dean Sherry Journal: J Am Chem Soc Date: 2018-12-11 Impact factor: 15.419