1H-15N HSQC spectra of polycystin-2-(680–796). The sample conditions were: 0.25 mm polycystin-2-(680–796) in 10 mm potassium phosphate buffer, pH 6.8, 500 mm NaCl, 2 mm dithioerythritol, and 0.1 mm DSS containing 90% H2O and 10% D2O. Temperature 293 K. Before (left) and after (right) the addition of 1.00 mm CaCl2. In bold letters peaks of the predicted EF-hand, in thin and italic letters are those of the second EF-hand.