Journal of Neuroscience, Vol 10, 317-322, Copyright © 1990 by Society for Neuroscience
Multiple GTP-binding proteins from cholinergic synaptic vesicles
JK Ngsee, K Miller, B Wendland and RH Scheller
Department of Biological Sciences, Stanford University, California 94305.
Cholinergic synaptic vesicles purified from the electric organ of the
marine ray, Discopyge ommata, contain 2 different size classes of GTP-
binding proteins: one or more with an apparent molecular weight (MW)
between 37 and 41 kDa, and 3 major and at least 2 minor proteins with MW
between 20 and 29 kDa. These GTP-binding proteins were detectable using the
alpha 32P-GTP overlay technique and covalent modification with bacterial
toxins. The higher MW GTP-binding proteins are ADP- ribosylated by
pertussis toxin and 2 of the lower MW GTP-binding proteins are sensitive to
botulinum toxin.