Novel Hydroxytryptophan-Based Gd Chelating Substrate for Imaging Myeloperoxidase Activity.

Alexei A. Bogdanov¹, Yang Xie, Mohammed S. Shazeeb

Myeloperoxidase (MPO) is one of the imaging targets that has clear outcome- predictive value in myocardial infarction and stroke. We previously synthesized and tested several paramagnetic complexes of mono- and bis- amides of macrocyclic and linear chelates that sense MPO activity. We report a novel paramagnetic reducing substrate of MPO resulting in enzyme-mediated increase of Gd relaxivity. Bis-HTrp-DTPA(Gd) has high water solubility and undergoes MPO-specific conversion into protein - reactive intermediates. We anticipate it to be an efficient sensor for in vivo imaging of MPO activity due to potential binding to tissue proteins in inflammatory lesions