TABLE 5 



Biochemical Differences between Esterases 

 i. aliesterases (substrates: esters of n-free alcohols) 



1. Substrate preferences: 



a) Chain length of fatty acid*' ^ 



h) Branching of chain of fatty acid*. . 



c) Ahphatic or aromatic nature of 

 fatty acid* 



d) Nature of alcohol moiety 



e) Rates of hydrolysis of nitrophenol 

 esters of C2-C5 fatty acids° 



/) Optical isomers'^' ® 



2. Activators and inhibitors: 



a) Quinine^' e- i^- » 



6) Arsanilic acid^' S' ' 



c) FluorideJ' ^' ' 



d) Bile acids^' ^' ^ 



A. Lipase 



Long (> 12) 

 Straight chain 



Aliphatic 

 Glycerol 



B. Esterase 



Short (< 12) 

 Iso chain 



Aromatic 

 Monohydric alcohols 



2<3<4<5 2<3>4>5 



The two types of enzymes often favor 

 opposite optical isomers in an unpre- 

 dictable way. 



Inhibition 

 No effect 

 Slight inhibition 

 Activation 



No effect 

 Inhibition 

 Marked inhibition 

 Inhibition 



II. CHOLINESTERASES (SUBSTRATES: ESTERS OF CHOLINE) 



1. Substrate preferences'' . 



2. Optimal substrate concentration" . 



3. Selective inhibitorsP 



A. So-called True 



or Specific Cho- 



linesterase 



Acetylcholine, 



mecholyl 

 Low (±10-3 5 M) 

 Nitrogen mus- 

 tard 



B. So-called Pseudo- or 



Nonspecific Cholines- 



terase™ 



Other choline esters 



High (± 10-2 M) 

 Diisopropylfluoro- 



phosphate, per- 



caine^ 



a Terroine, E. F.: Ann. sci. nat., zool., X^ ser., 4: 1, 1942. 



^ Scli0nheyder, F., and Volqvartz, K.: Enzymologia, 11: 178, 1944. 



•= Huggins, C, and Moulton, S. H.: J. Exper. Med., 88: 169, 1948. 



d Willstatter, R., and Memmen, F.: Ztschr. f. physiol. Chem., 138:216, 1924. 



e Ammon, R.: Fermentforsch., 11:459, 1929-30; Rona, P., and Ammon, R.: Ergebn. d. Enzym- 

 forsch.,2:50, 1933. 



f Rona, P., and Pavlovic, R.: Biochem. Ztschr., 130:225, 1922. 



8 Rona, P., and Pavlovic, R.: Biochem. Ztschr., 134:108, 1923. 



b Rona, P., and Takata, M.: Biochem. Ztschr., 134:118, 1923. 



i Rona, P., and Haas, H. E.: Biochem. Ztschr., 141:222, 1923, 



i Kastle, J. H., and Loevenhart, A. S.: Am. Chem. J., 24:491, 1900; Loevenhart, A, S., and Peirce, 

 G,: J. Biol. Chem., 2:397, 1906-7. 



k Nachlas, M. M., and Seligman, A. M.: J. Biol. Chem., 181:343, 1949. 



1 Seligman, A. M., Nachlas, M. M., and Mollomo, M. C: Am. J. Physiol., 159:337, 1949. 



™ Click, D.: Science, 102:100, 1945. 



" Nachmansohn, D., and Rothenberg, M. A.: Science, 100:454, 1944. 



o Mendel, B., Mundell, D. B., and Rudney, H.: Biochem. J., 37:473, 1943; Augustinsson, K. B.: 

 Nature, 162:194, 1948. 



p Mendel. B., and Hawkins, R. D.: Biochem. J., 41 :22, 1947; Adams, D. H., and Thompson, H. S.: 

 Biochem. J., 42:170, 1948; Adams, D. H.: Biochim. et biophys. acta, 3:1, 1949. 



<i Zeller, E. A., and Bissegger, A,: Helvet. chim. acta, 26: 1619, 1943. 



