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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 3
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
).
1
Journ. of Physiol. 40 (1910).
2
Gaz. hebciomadaire, 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
Kiihne, Verh. 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. Biologie, 28; Schwarzschild, Hofmeister’s Beitrage, 4.
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