182 



ASPECTS OF BIOCHEMICAL EFFECTS 



TABLE 1 



Protective Power per Molecule of Various Substances Relative to Carboxy- 



Peptidase (CP) and Dinucleotide (DN) 



Protector 



Thiourea 



Sodium formate 



Dimethyltbiourea 



Glucose 



Dimethylurea 



Egg albumin 



Alloxan 



Sodium mesoxalate 



Sodium oxalate 



Urea 



Molecular 

 Weight 

 76 

 68 

 104 

 180 

 88 

 ~40,000 

 142 

 152 

 134 

 60 



Protective 



Power 

 withCP 



4.7 



3.1 



1.9 



0.79 



0.4 

 0.24 

 2.1 X 10-2 



2.4 X 10-2 

 2.0 X 10-3 



7.5 X 10-" 



Protective 

 Power 



with DN 

 2.1 

 0.74 



0.21 



0.21 



Ratio of 



Protective 



Power with 



DN and CP 



2.2 



4.2 



3.8 



1.1 



It has been found that the protective power per unit mass of protector 

 is sometimes not a constant but dechnes relatively with increasing con- 

 centrations of the protector (Fig. 3). I shall return to this point later. 



?P3 



© A Dimethylurea with carboxy- peptidase, 30 Mg/ml 

 o B Glucose with carboxyrpeptidase, 30 Mg/ml 

 • C Glucose with carboxy- peptidase, 90 fxg/m\ 



10^ 



10 



10" 10 



Concentration, Mg/ml 



Fig. 3. Protective power of various substances per unit of mass protector. Repro- 

 duced by permission from Brit. J. Cancer, 3: 31, 1949. 



The specificity of the indirect action could also be demonstrated for 

 the deamination reaction (5) in which the deamination varies in relation 

 to the configuration of the remainder of the amino acids. These experi- 



