Specific, water-soluble polypeptides in identified neurons of Aplysia californica

Application of an ethylene glycol lysis technique to extract water-soluble, low molecular weight polypeptides in Aplysia neurons, was used in conjunction with microgradient gel electrophoresis and micro-isoelectric focusing, to identify unique polypeptides in specific, identified neurons. The polypeptides found in neurons R15, R3-13, R14, and the bag cells were particularly abundant, consistent with the previously suggested neurosecretory role for these cells. Water extraction of the strongly basic polypeptides (pI 10.7) in R3-13 and R14 required an acidic lysis medium.