Fig. 1. Insertion of VDAC channels into a planar phospholipid membrane. The membrane was made by the monolayer method of Montal and Mueller as per Schein et al. (1976) using soybean phospholipids. The aqueous solution was 1.0 M KCl, 5 mM CaCl2. The transmembrane voltage was clamped at 10 mV beginning where indicated. Five microliters of Triton X100 solubilized N. crassa VDAC were added at the stirring artefact. The first conductance increment is the insertion of a triplet of VDAC channels, a common occurrence for N. crassa VDAC. Reproduced with permission from Colombini (1980a).