ONE F1G:IJRE
Analysis of the axoplasm of squid giant nerve fibers has shown that chloride is present in the intracellular phase but that some 75430% of the anions must be organic (Bear and Schmitt, '39 ; Webb and Young, '40; Steinbach, '41). Schmitt, Rear and Silher ('39) found a chloride deficit of about 70% in deproteinized lobster nerve extracts, hence protein binding was excluded as a possible source of organic anions. Formol titrations, ninhydrin color reactions, and coilsiderations of dry weight indicated that the anion deficit may be accounted for to a large extent by the presence of a high concentration of free amino acids. Further studies on lobster nerve (Silber and Schmitt, '40) established the fact that there is a high concentration of free amino acids in this nerve (0.30 m.eq. NH, and 0.38 m.eq. COOH per gram tissue water). An excess of carboxyl groups supported the suggestion that at least a portion of the amino acids is available for base binding. The present communication is concerned with the isolation arid identification of the amino acids in lobster nerve.
METHODS AND PROCEDURE
Claw and leg nerves of lobsters were dissected as rapidly as possible and weighed after brief blotting. They were then frozen, macerated, and ground repeatedly with sand in 50 ml. portions of alcohol-ether ( 3 : 1) until 2 liters of filtrate were obtained. The residue was then successively extracted with 1 liter of 80% alcohol, 50% alcohol, and water. These four extracts were analyzed for amino and carboxyl groups by the maiionietric methods of Van Slyke as were subsequent extractions of the dry residues froiii the first two after evaporation in vacuo.