Two polypeptide toxins with opposite effects on calcium uptake in bovine chromaffin cells: isolation from the venom of the marine snail Conus distans.
Two polypeptide toxins which modulate the uptake of 45Ca2+ in bovine chromaffin cells were isolated from the venom of the marine snail Conus distans. The molecular weights were estimated by gel electrophoresis and gel filtration to be 25.5 and 24 kDa, respectively. The purified proteins were electrophoretically homogeneous. The 25.5 kDa-component caused a concentration-dependent increase of the initial rate of 45Ca2+ uptake, but it had no effect on the stimulation evoked uptake. The 24 kDa-component produced the opposite effects; it caused a concentration-dependent inhibition of the stimulation evoked 45Ca2+ uptake, but it did not affect the initial rate.
Partoens
P
P
Laboratory of Neuropharmacology, University of Anwerp, Wilrijk, Belgium.
Wang
J M
JM
Coen
E P
EP
Vauquelin
G
G
De Potter
W P
WP
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000187:drug effects* / Q000378:metabolism; D007473:Ion Channels / Q000187:drug effects; D008978:Mollusk Venoms / Q000633:toxicity*
D007473:Ion Channels; D008978:Mollusk Venoms; D002118:Calcium