TY - JOUR
T1 - Fusion of phospholipid vesicles with planar phospholipid bilayer membranes
T2 - I. Discharge of Vesicular Contents across the Planar Membrane
AU - Zimmerberg, Joshua
AU - Cohen, Fredric S.
AU - Finkelstein, Alan
PY - 1980/3/1
Y1 - 1980/3/1
N2 - Multilamellar phospholipid vesicles are introduced into the as compartment on one side of a planar phospholipid bilayer membrane. The vesicles contain a water-soluble fluorescent dye trapped in the aqueous phases between the lamellae. If a vesicle containing n lamellae fuses with a planar membrane, an n-I lamellar vesicle should be discharged into the opposite trans compartment, where it would appear as a discernible fluorescent particle. Thus, fusion events can be assayed by counting the number of fluorescent particles appearing in the trans compartment. In the absence of divalent cation, fusion does not occur, even after vesicles have been in the cis compartment for 40 min. When CaCl2 is introduced into the cis compartment to a concentration of ≤20 mM, fusion occurs within the next 20 min; it generally ceases thereafter because of vesicle aggregation in the cis compartment. With approximately 3 × l08 vesicles/cm 3 in the cis compartment, about 25-50 fusion events occur following CaCl2 addition. The discharge of vesicular contents across the planar membrane is the most convincing evidence of vesicle-membrane fusion and serves as a model for that ubiquitous biological phenomenon--exocytosis.
AB - Multilamellar phospholipid vesicles are introduced into the as compartment on one side of a planar phospholipid bilayer membrane. The vesicles contain a water-soluble fluorescent dye trapped in the aqueous phases between the lamellae. If a vesicle containing n lamellae fuses with a planar membrane, an n-I lamellar vesicle should be discharged into the opposite trans compartment, where it would appear as a discernible fluorescent particle. Thus, fusion events can be assayed by counting the number of fluorescent particles appearing in the trans compartment. In the absence of divalent cation, fusion does not occur, even after vesicles have been in the cis compartment for 40 min. When CaCl2 is introduced into the cis compartment to a concentration of ≤20 mM, fusion occurs within the next 20 min; it generally ceases thereafter because of vesicle aggregation in the cis compartment. With approximately 3 × l08 vesicles/cm 3 in the cis compartment, about 25-50 fusion events occur following CaCl2 addition. The discharge of vesicular contents across the planar membrane is the most convincing evidence of vesicle-membrane fusion and serves as a model for that ubiquitous biological phenomenon--exocytosis.
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U2 - 10.1085/jgp.75.3.241
DO - 10.1085/jgp.75.3.241
M3 - Article
C2 - 6247417
AN - SCOPUS:0018876557
SN - 0022-1295
VL - 75
SP - 241
EP - 250
JO - Journal of General Physiology
JF - Journal of General Physiology
IS - 3
ER -