Separation of Hexone Bases. 



349 



acids which are predominantly acid, including aspartic and glu- 

 tamic acid, which migrate to the anode, (b) the basic amino acids 

 which include arginin, histidin and lysin, and which wander to 

 the cathode, and (c) the remaining amino acids, which on account 

 of the fact that their acid properties are about equally balanced 

 by their basic properties, remain in the center compartment. 



Since this method eliminates the reagents which, in other 

 methods, are required in order to separate the hexone bases, ex- 

 perimental work was carried out on a laboratory scale to determine 

 the general applicability of this method to the isolation of the 

 basic amino acids. 



The electrolytic cell consists of a rectangular w r ooden box 

 3 X 6 X 4-5 inches which was cut into three approximately equal 

 vertical sections. The membranes separating the compartments 

 consist of strips of linen cloth which were coated with gelatin by 

 immersion in a 30 per cent, solution of this substance and the gela- 

 tin was subsequently fixed by allowing the strips to remain in 

 formalin over night. After placing the membranes in position, 

 the three parts of the cell are clamped by means of bolts. For 

 the purposes of water-proofing, the cell was painted with asphalt. 

 Thin sheets of carbon were used instead of the iron electrodes 

 recommended by Ikeda and Suzuki. The latter were found to 

 dissolve at the anode and Fe(OH) 3 to precipitate in the cathode 

 solution, necessitating its subsequent removal. The fluid in the 

 center compartment was kept at the Ph indicated in the table by 

 the addition of small quantities of Ba(OH) 2 at frequent intervals. 

 Similarly the reaction of the cathode liquor was kept approxi- 

 mately neutral by the occasional addition of H 2 S0 4 . The tem- 

 perature of the solutions was kept below 35 0 C. by circulating a 

 stream of water through a test tube which was placed in the center 

 compartment, and by continuous agitation of the solution. Dis- 

 tilled water was placed in the anode and cathode compartments. 

 Electrolysis was effected by passing 1.5 amperes of the no- volt 

 circuit through the cell. 



The experiments were carried out with gelatin since this sub- 

 stance is a convenient source for arginin. The protein was hydro- 

 lyzed with the aid of 30 per cent. H2SO4 as suggested by Dakin, 3 



1 Dakin, H. D., J. Biol. Chem., 1920, xliv, 499. 



