158 



CHEMISTRY OF CYPRIDINA LUCIFERIN 



a basis for comparison with preparations of Cypridina luciferin of 

 higher degrees of homogeneity. 



In our hands, the amino acids, glutamic acid, glycine, threonine, 

 proline and leucine, isoleucine, or phenylalanine were identified in 

 acid hydrolyzates of Cypridina luciferin. Microbiological tests were 

 also performed on luciferin hydrolyzate by Dr. B. D. Davis of the U. S. 

 Public Health Service using a series of amino acid auxotrophes of 





2700 2800 2900 



WAVE NUMBERS IN cm 



Fig. 9. 



3000 

 I 



3100 



B. coll; the presence of all the above amino acids was confirmed and, 

 in addition, evidence was found for the presence of methionine, argi- 

 nine, histidine, valine, and tyrosine. 



Dr. Kauzmann: Have you tested for the presence of sulfhydryl and 

 disulfide groups in Cypridina luciferin? 



Dr. Tsuji: Sulfhydryl groups do not appear to be present in so far 

 as tests with alkaline nitroprusside and p-chloromercuribenzoic acid 

 are concerned. Mason also was not able to detect sulfhydryl groups 

 with alkaline nitroprusside. However, we have observed that when 

 the sulfhydryl blocking agent, N-ethyl maleimide, is allowed to stand 



