Ultrastructural visualization of Na+-channel associated [125I]alpha-scorpion toxin binding sites on fetal mouse nerve cells in culture.
Purified neurotoxin II from the scorpion Androctonus australis Hector (alpha-ScTx) has previously been shown to bind specifically to the voltage-sensitive Na+ channels of excitable cells. Recent studies, using high specific activity 125I-labeled alpha-ScTx, demonstrated specific binding to neuronal cells derived from fetal mouse brains. In the present study, 125I-labeled alpha-ScTx was used to localize the voltage-sensitive Na+ channels in cultured fetal mouse brain cells. By quantitative electron microscope autoradiography we demonstrate that specific alpha-ScTx binding sites are selectively located at the plasma membrane. Estimates of their density revealed that neurites at 13 days in vitro carry at least 6 X more specific alpha-ScTx sites than cell body membrane.
J A
JA
Boudier
Y
Y
Berwald-Netter
H D
HD
Dellmann
J L
JL
Boudier
F
F
Couraud
A
A
Koulakoff
P
P
Cau
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D001921:Brain; D002462:Cell Membrane / Q000378:metabolism; D005333:Fetus; D007473:Ion Channels / Q000378:metabolism*; D051379:Mice; D008854:Microscopy, Electron; D009474:Neurons / Q000378:metabolism*; D011950:Receptors, Cholinergic / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels
D007473:Ion Channels; D011950:Receptors, Cholinergic; D015222:Sodium Channels; C029574:scorpion toxin receptor; D012964:Sodium