30 II. DIGESTION AND ABSORPTION OF FATS 



Table 2 



Comparison of the General Properties of Cholinesterases Derived from the 



Erythrocytes and Serum of Hitman Blood and from Cobra Venom 



Erythrocyte- Serum- 



e-type s-type Coluber- 



Property "True" "Pseudo" e-type 



Optimal pH* 7.5-8.0 8.0 



Activation by NaCl a + 



Inhibition by high substrate concentra- 

 tions....' + a > b a >*> +• 



Inhibition by high substrate concentra- 

 tions + alcohol d 



Optimum concentration for inhibition*. 0.25 X 10" 6 M >0.25 X 10~ 4 M 



Hydrolysis of: 



Acetyl-/3-methylcholine +' 0/ +' 



Benzoylcholine 0' +' 0»-* 



Butyrylcholine 0*' +' h 



Tributyrin O*-'" + e •<'• , ' ft 



Triacetin* + + 



Ethylchloroacetate 1 + + 



Ethylchloroacetate + eserine 1 + 



,8-Ethylchloroacetate* ++ + 



^-Ethylchloroacetate -f eserine' -f- 



Ethoxyethanol acetate" 1 ++ + 



Inhibition by: 



Eserine +' + l +' 



/3,/?-Dichlorodiethyl-iV-methylamine n + 



Nu-1250°. p + 



• G. A. Alles and R. C. Hawes, J. Biol. Chem., 183, 375-390 (1940); R. C. Hawes and 

 G. A. Alles, /. Lab. Clin. Med., 26, 845-853 (1941). 



b K. B. Augustinsson, Acta Physiol. Scand., 15, Suppl. 52, 1-182 (1948). 



c E. A. Zeller and A. Maritz, Heir. Physiol, et Pharmakol. Acta, 3, C 19-C 20 (1945). 



d K. P. Fellowes, J. P. Rutland, and A. Todrick, Biochem. J., 47, xx (1950). 



e E. A. Zeller and A. Bissegger, Heir. Chim. Acta, 26, 1619-1630 (1943). 



' B. Mendel, D. B. Mundell, and H. Rudney, Biochem. J.. 37, 473-476 (1943). 



F. Bovet-Nitti, Experientia, 3, 283-286 (1947). ' 

 h L. A. Mounter, Biochem. J., 49, xlv-xlvi (1951 ). 



* F. Kalsbeek. J. A. Cohen, and B. R. Bovens, Biochim. et Biophys. Acta, 5, 548-560 

 (1950). 



t B. Mendel and H. Rudney, Biochem. J., 37, 59-63 (1943). 

 k P. Holton, Biochem. J., 43, xiii (1948). 



1 R. A. McNaughton and E. A. Zeller, Proc. Soc. Exptl. Biol. Med., 70, 165-167 (1949). 

 "> E. A. Zeller, G. A. Fleischer, R. A. McNaughton, and J. S. Schweppe, Proc. Soc. 



Exptl. Biol. Med., 71, 526-529 (1949). 



« D. H. Adams and R. H. S. Thompson, Biochem. J., 42, 170-175 (1948). 



° Physostigmine analogue, N-p-chlorophenyl-iV-methylcarbamate of m-hydroxy- 

 phenvftrimethylammonium bromide (Hoffmann-LaRoche, Nu-1250). 



v R. D. Hawkins and B. Mendel, Biochem. ./., 44, 260-264 (1949). 



