152 



CHEMISTRY OF CYPRIDINA LUCIFERIN 



Luciferin isolated by paper electrophoresis gave a negative nin- 

 hydrin reaction, but a positive test for protein or polypeptide by the 

 method of Lowry et al. (1951), using the Fohn-Ciocalteu phenol 

 reagent, and the test was accompanied by a loss of luminescent ability. 

 A sample of this luciferin was hydrolyzed by refluxing with 6 N HCl 

 for 16 hours. The hydrolyzate, on evacuating to dryness, gave a very 

 strong ninhydrin test, as did hydrolyzates from two other areas of the 



«.o 



— 5.5 



I/) 



CO 



< 

 a: 



o 



Volu«l in portntheftt 



reprtient 

 fflicrt fflolti amino ecid 



Ammonio (11.53) 



2.0 



1.5 



1.0 



I 0.5 



oil ofnino Qcidt 

 tmtr^ing b*(or« 

 tyrotint 



1 



Tyrotint 



+ 

 PKenylolonint 



Uynre (0.88) 



Arginine 

 (0.24) 



25 50 75 100 125 

 pH5 

 i-25"C-|>- pM6 8,25*C|pnosphat« -.|. 



a. 



-1- 



150 175 200 225 

 PH 6 5,25*C, citiole ■ 



EFFLUENT cc. 



Hv^ 



Fig. 7. Isolation of basic amino acids from same luciferin hydrolyzate as shown 

 in Fig. 6. Chromatography was carried out on Dowex 50 column 0.9 X 15 cm 

 according to the method of Moore and Stein (1951). The column was op- 

 erated in the sodium form. The pH, the buffers used as eluants, and tem- 

 perature of operation of the column are indicated. The first peak may be 

 taurine, while the second peak represents all the amino acids emerging be- 

 fore tyrosine. 



paper, one on each side of the luciferin band. The amount of luciferin 

 isolated by paper electrophoresis was not sufficient to carry out amino 

 acid analysis of the hydrolyzate on Dowex 50 columns. 



Luciferin isolated by paper chromatography was also hydrolyzed 

 with 6 N HCl for 16 hours and evacuated to dryness in a vacuum 

 desiccator. The residue gave a very strong ninhydrin test, whereas 

 before hydrolysis only a faint test was obtained. This hydrolyzate also 

 showed some luminescence with luciferase and a characteristic yellow 



