COMPARISON OF 12,000 DALTON PROTEINS SYNTHESIZED BY APLYSIA NEURONS L11 AND R15

The 12,000 dalton proteins of neurons L11 and R15 of the Aplysia abdominal ganglion were labeled by incubation of the ganglion in [3H]leucine and compared in terms of their subcellular localization, solubility in various media and molecular charge. Both proteins were cytoplasmic constituents. Their solubility behavior was identical: both were insoluble in aqueous media of low and high ionic strength as well as chloroform-methanol, and both were solubilized by Triton X-100 + urea and by LIS [lithium diiodosalicylate]. They were essentially identical in molecular weight as determined by SDS [sodium dodecyl sulfate] gel electrophoresis but differed by a single charge per molecule at low pH. The broad similarity between these proteins suggested that they could serve similar functions, while the observed charge difference could be important in terms of previously discovered differences in their processing.