TABLE 1.

Apparent molecular masses and relative hydrodynamic radii of polycystin-2-(680–796) in the presence and absence of Ca²⁺ ions

The samples contained 200 μm polycystin-2-(680–796) in 5 mm Tris-HCl, pH 6.8, 500 mm NaCl, 0.1 mm DSS in 90% H₂O, and 10% D₂O. Data were recorded in the absence and presence of 2 mm CaCl₂. Data were evaluated as described by Munte et al. (22).

Compound	Da	Rh/Rh,DSSb	Mexpc	Mcalcd
	10−12m2·s−1		g·mol−1	g·mol−1
Polycystin-2-(680–796)	1.51 ± 0.04	4.98 ± 0.14	24,249 ± 2,045	13,515
Polycystin-2-(680–796)·2Ca2+	2.09 ± 0.09	3.60 ± 0.17	9,160 ± 1,297	13,595
Polycystin-2-(680–796), MgCl2	1.47 ± 0.05	5.15 ± 0.17	26,742 ± 0,902	13,515

^a The diffusion constant was quantified by measuring the signal decay in 99.9% D₂O, 0.1% H₂O as a function of the gradient strength and assuming a diffusion constant of HDO of 1.872·10⁻⁹·m²·s⁻¹ at 298 K.

^b Ratio of the hydrodynamic radii of polycystin-2 and DSS.

^c Apparent molar mass of polycystin-2 experimentally obtained using DSS (196.34 g mol⁻¹) as reference.

^d Molar mass calculated from the sequence.