BIOLOGICALLY ACTIVE PEPTIDES IN BRAIN AND FURTHER PURIFICATION OF NERVESIDE

Abstract

A peptide, nerveside, was found in the dog brain. Consistent high concentrations were found in the cerebral cortex and the hypothalamus. Sheep brains were extracted and a stock acetone solution of nerveside was prepared according to the method described by Toh (1964). This thesis describes the further purification of stock acetone preparation of nerveside by passing an aqueous solution through Cellex-E cellulose, an anion exchanger and Carboxy-methyl cellulose, a cation-exchanger. The material was fractionated on Bio-gel P2 and then subjected to electrophoresis on Pevikon C-870. In this way, the stock acetone solution of nerveside was found to contain three active peptides. One of them constituted 73.8 % of their total biological activity and was identified as nerveside itself (here called peptide B). The two remaining peptides, peptide A and peptide C, accounted for 21.7 % and 4.5 % of their total biological activity respectively. They appeared to be minor constituents which would not be detectable if small amounts of brain tissue were used for extraction.