Fig. 3

ManICS1 reports calcium-dependent MRI signal changes in buffer and MnICS1-AM undergoes enzymatic hydrolysis. a T₁-weighted images of 40 µM ManICS1 with addition of varying micromolar concentrations of CaCl₂ (top) or MgCl₂ (bottom) in MOPS buffer, pH 7.4. b Relaxivity changes corresponding to conditions in a. Ligand-depleting bimolecular binding models were used to generate the fitted curves shown. Error bars denote SD of four measurements. c Reversed phase HPLC traces of 10% (v/v) HEK293 cell lysate (gray), ManICS1(blue), ManICS1-AM (solid red), ManICS1-AM treated with cell lysate for 5 h (dotted red), ManICS1-Et (solid green), ManICS1-Et treated with cell lysate for 5 h (dotted green). Vertical dashed line indicates expected elution time of ManICS1