Flavell, Robert R. Kothari, Paresh Bar-Dagan, Maya Synan, Michael Vallabhajosula, Shankar Friedman, Jeffrey M. Muir, Tom W. Ceccarini, Giovanni Site-Specific <sup>18</sup>F-Labeling of the Protein Hormone Leptin Using a General Two-Step Ligation Procedure The protein hormone leptin acts to regulate body fat and energy expenditure. Resistance to this hormone is implicated in human obesity and its pathophysiological consequences. In order to gain insight into the mechanism of leptin resistance, an <sup>18</sup>F-labeled derivative was developed to study the biodistribution of the hormone using positron emission tomography (PET). A two-step, site specific ligation approach was developed for this purpose, in which an aminooxy-reactive group was incorporated at the C-terminus of leptin using expressed protein ligation (EPL), which was subsequently derivatized with [<sup>18</sup>F]fluorobenzaldehyde using an aniline-accelerated radiochemical oximation reaction. The modified hormone was shown to be biologically active <i>in vitro</i> and <i>in vivo</i>, and it was applied to PET imaging in <i>ob</i>/<i>ob</i> mice. These protocols will allow for the routine production of site-specifically <sup>18</sup>F radiolabeled leptin, as well as other proteins, for use in PET imaging in systems from mouse to man. leptin;resistance;EPL;protein;Protein Hormone Leptin;PET imaging;hormone;ligation;positron emission tomography 2008-07-16
    https://acs.figshare.com/articles/journal_contribution/Site_Specific_sup_18_sup_F_Labeling_of_the_Protein_Hormone_Leptin_Using_a_General_Two_Step_Ligation_Procedure/2927491
10.1021/ja801666z.s002