ENZYMES CONCERNED WITH DIGESTION OF LIPIDS 59 



russelli) , 204,334 the southwest European viper (Vipera aspis), 3i0 as well as 

 from a large additional group of less common members of the Vipera fam- 

 ily. 341 Marnay and Nachmansohn 342 noted the presence of cholinesterase 

 in the muscles of the foot, leg, and tail of the green lizard (Lacerta viridis). 



f . Acetylesterase in Citrus: An enzyme which hydrolyzes acetic acid 

 esters in oranges, lemons, and grapefruit has been described by Jansen 

 and co-workers. 343 The highest concentration of this acetylesterase 

 occurred in the yellow outside coat (flavedo). It decreased progressively 

 toward the center of the fruit. The distribution was similar to that of 

 phosphatase but differed from that of pectinesterase. Although acetyl- 

 esterase hydrolyzes acetylcholine, it cannot be considered to be a cholin- 

 esterase, since it is not inhibited by eserine. The rate of hydrolysis of 

 tributyrin was only 4% of that of triacetin, while monobutyrin was split at 

 a rate which was only 1% of that of monoacetin. All aliphatic acetate 

 esters were hydrolyzed. However, olive oil was not attacked. The 

 enzyme was found to be unstable at a pH under 4.0 and was inactivated 

 at temperatures above 35°C. 



(h) Preparation of Cholinesterases. Aldridge 246 described a convenient 

 method for the preparation of true cholinesterase. In preparing this 

 type of enzyme from erythrocytes, Paleus 344 reported that cholinesterase 

 is so firmly bound to the membrane that it is extremely difficult to elute 

 it to any significant degree. Mentha and co-workers 345 noted that, when 

 pseudoagglutination is brought about by treating erythrocytes with dilute 

 alkali, the maximum esterase extraction can be accomplished with a mini- 

 mum hemolysis. Ord and Thompson 346 prepared soluble cholinesterases 

 from mammalian heart and brain. Bodansky, 347 in his review on cholin- 

 esterase, cites Mendel and Rudney, 186 who reported the preparation of a 

 cholinesterase from the brain of the dog. Mendel and Mundell 211 described 

 a procedure for the purification of cholinesterase from dog pancreas. A 

 method for the purification of pseudocholinesterase from horse serum has 

 been outlined by Strelitz. 348 The cholinesterase present in the electric 

 organ of Electrophorus electricus (electric eel) was prepared in a highly 



340 E. A. Zeller, V. Kocher, and A. Maritz, Helv. Physiol. Pharmacol. Acta, 2, C63-C64 

 (1944). 



341 E. A. Zeller, Experientia, 8, 375-376 (1947). 



342 A. Marnay and D. Nachmansohn, Compt. rend. soc. bioi, 125, 489-490 (1937). 



343 E. F. Jansen, R. Jang, and L. R. MacDonnell, Arch. Biochem., 15, 415-431 (1947). 



344 S. Paleus, Arch. Biochem., 12, 153-154 (1947). 



346 J. Mentha, H. Sprinz, and R. Barnard, J. Biol. Chem., 167, 623 (1947). 

 346 M. G. Ord and R. H. S. Thompson, Biochem. J., 49, 191-199 (1951). 

 317 O. Bodansky, Ann. N. Y. Acad. Sci., 47, 521-547 (1946). 

 348 F. Strelitz, Biochem. J., 88, 86-88 (1944). 



