Internal composition 10 Mm BaCl2 (external) Intensity (355/460) mean (n=2) ±s.d. MjK2, 1 M KCl, pH4 + 9192.15 2124.87 MjK2, 0.1 M KCl, pH4 + 7284.97 2684.83 MjK2, 0.01 M KCl, pH4 + 5580.07 187.98 MjK2, 1 M KCl, pH8 + 5434.06 1441.39 MjK2, 0.1 M KCl, pH8 + 4949.42 1277.84 MjK2, 0.01 M KCl, pH8 + 4125.7 2071.16 MjK2, 1 M KCl, 25 mM MgCl2, pH4 + 1970.32 477.66 MjK2, 1 M KCl, 25 mM MgCl2, pH8 + 3854.24 1593.28 MjK2, 1 M KCl, 25 mM CaCl2, pH4 + 3646.67 938.47 MjK2, 1 M KCl, 25 mM CaCl2, pH8 + 8831.86 708.26 MjK2, 1 M KCl, 0.1 mM cAMP, pH4   -14885.43 1302.8 MjK2, 1 M KCl, 0.1 mM cAMP, pH8 + 4683.14 919.53 MjK2, 1 M KCl, pH4 - -18902.9 3328.44 Liposomes, 1 M KCl, pH4 + -1977.27 854.84

Table 1: Effect of the internal composition of channelosomes on the MjK2 activity. The optical activity of MjK2 or control liposomes was monitored as described in Figure 4.