A New Gadolinium-Based MRI Zinc Sensor

作者：Esqueda Ana C; Lopez Jorge A; Andreu de Riquer Gabriel; Alvarado Monzon Jose C; Ratnakar James; Lubag Angelo J M; Sherry A Dean; De Leon Rodriguez Luis M^*

来源：Journal of the American Chemical Society, 2009, 131(32): 11387-11391.

DOI：10.1021/ja901875v

The properties of a novel Gd(3 )-based MRI zinc sensor are reported. Unlike previously reported Gd(3 )-based MRI contrast agents, this agent (GdL) differs in that the agent alone binds only weakly with human serum albumin (HSA), while the 1:2 GdL:Zn(2 ) ternary complex binds strongly to HSA resulting in a substantial, 3-fold increase in water proton relaxivity. The GdL complex is shown to have a relatively strong binding affinity for Zn(2 ) (K(D) = 33.6 nM), similar to the affinity of the Zn(2 ) ion with HSA alone. The agent detects as little as 30 mu M Zn(2 ) in the presence of HSA by MRI in vitro, a value slightly more than the total Zn2 concentration in blood (similar to 20 mu M). This combination of binding affinity constants and the high relaxivity of the agent when bound to HSA suggests that this new agent may be useful for detection of free Zn(2 ) ions in vivo without disrupting other important biological processes involving Zn(2 ).

• 出版日期2009-8-19