Effects of various counterions.
(A) Area per molecule at π = 30mN/m of L-α PIP2 on HEPES-buffered subphase with 250 mM salt; Mean ± SE, n=5.
(B) π-Area isotherms of L-α PIP2 HEPES-buffered subphase, pH 7.4, 30°C (solid line) and same conditions plus 250 mM CaCl2 (dashed line); (inset) quantification of the effects of 250 mM CaCl2 and MgCl2; mean ± SE, n=4.