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Medizin - Open Access LMU - Teil 07/22 Podcast
Reductive chain separation of botulinum A toxin — a prerequisite to its inhibitory action on exocytosis in chromaffin cells

Reductive chain separation of botulinum A toxin — a prerequisite to its inhibitory action on exocytosis in chromaffin cells

Medizin - Open Access LMU - Teil 07/22 vor 37 Jahren

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Cleavage of the disulfide bond linking the heavy and the light
chains of tetanus toxin is necessary for its inhibitory action on
exocytotic release ofcatecholamines from permeabi1ized chromaffin
cells [(1989) FEBS Lett. 242, 245-248; (1989) J. Neurochern., in
press]. The related botulinum A toxin also consists of a heavy and
a light chain linked by a disulfide bond. The actions ofboth
neurotoxins on exocytosis were presently compared using
streptolysin O-permeabilized bovine adrenal chromaffin cells.
Botulinum A toxin inhibited Ca2 +-stimulated catecholamine release
from these cells. Addition of dithiothreitollowered the effective
doses to values below 5 nM. Under the same conditions, the
effective doses of tetanus toxin were decreased by a factor of
five. This indicates that the interchain S-S bond of botulinum A
toxin must also be split before the neurotoxin can exert its effect
on exocytosis.