TRYPSIN. 503 



filtrate. 1 In regard to the synthetic action of pancreatic lipase see 

 page 60. 



The fatty acids which are split off by the action of the pancreatic 

 juice combine in the intestine with the alkalies, forming soaps, which 

 have a strong emulsifying action on the fats, and thus the pancreatic 

 juice becomes of great importance in the emulsification and the absorp- 

 tion of the fats. 



Trypsin. The action of the pancreatic juice in digesting proteins 

 was first observed by BERNARD, but first proved by CoRViSART. 2 It 

 depends upon a special enzyme called, by KUHNE, trypsin. This enzyme 

 as previously explained, does not occur in the gland as such, but as 

 trypsinogen. According to ALBERTONI S this zymogen is found in 

 the gland in the last third of the intra-uterine life. Enzymes more or 

 less like trypsin occur in other organs, and are very widely diffused in 

 the vegetable kingdom, 4 in yeast and in higher plants, and are also formed 

 by various bacteria. The enzymes similar to trypsin occurring in the 

 plant kingdom are, according to VINES, a mixture of peptases, which 

 transform the proteins into peptone, and ereptases, which split the pep- 

 tones into amino-acids. 



As we know of so-called antienzymes for other enzymes, so we also have anti- 

 trypsins, and not only in the intestinal canal but also in the blood-serum (see page 

 63). The results as to the possibility of producing antitrypsins by immuniza- 

 tion, is still disputed. 



Trypsin, like other enzymes, has not been prepared in a pure con- 

 dition. Nothing is positively known in regard to its nature, but as 

 obtained thus far it shows a variable behavior (KUHNE, KLUG, LEVENE, 

 MAYS, and others). At least it does not seem to be a nucleoprotein, and 

 trypsin has also been obtained which did not give the biuret test (KLUG, 

 MAYS, SCHWARZSCHILD). Trypsin dissolves in water and glycerin, while 

 KUHNE 's trypsin was insoluble in glycerin. It is very sensitive to heat, 

 and even the body temperature gradually decomposes it (VERNON, MAYS). 

 In neutral solution it becomes inactive at 45 C. In dilute soda solu- 

 tion of 3-5 p. m. it is still more readily destroyed (BIERNACKI, VERNON 5 ). 



Journ. of Physiol. 40 (1910). 



2 Gaz. hebdomadaire, 1857, Nos. 15, 16, 19, cited from Bunge, Lehrbuch, 4, Aufl., 

 185. 



3 See Maly's Jahresber.,'8, 254. 



4 In this connection see Vines, Annals of Botany, 16, 17, 18, 19, 22, and 23, and 

 Oppenheimer, Die Fermente, 1910. 



5 Kuhne, Verb. d. naturh.-med. Vereins zu Heidelberg (N. F.), 1, 3; Klug, Math, 

 naturw. Ber. aus Ungarn., 18, 1902; Levene, Amer. Journ. of Physiol., 5; Mays, 

 Zeitschr. f. Physiol. Chem., 38; Vernon, Journ. of Physiol., 28 and 29; Biernacki, 

 Zeitschr. f. Biologic, 28; Schwarzschild, Hofmeister's Beitrage, 4. 



