Fj. Moyano et L. Savoie, Comparison of in vitro systems of protein digestion using either mammal orfish proteolytic enzymes, COMP BIOC A, 128(2), 2001, pp. 359-368
Citations number
27
Categorie Soggetti
Animal Sciences",Physiology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
Hydrolysis of three different proteins by either crude fish digestive extra
cts or purified mammal proteases was assayed using two different in vitro s
ystems. The closed system was a modification of the pH-stat method includin
g a previous acid digestion. The open system used a digestion cell containi
ng a semi-permeable membrane which allowed continuous separation of the fin
al products of hydrolysis with a molecular cut-off of 1000 Da. Assays in bo
th systems resulted a similar arrangement of the tested proteins in relatio
n to their ability to be hydrolyzed, with casein > fish meal greater than o
r equal to soybean meal. With the exception of casein, no significant diffe
rences were found between results produced by any of the enzyme sources usi
ng the closed system. In constrast, significantly higher hydrolysis of all
proteins was produced by mammal enzymes under conditions operating in the o
pen system. Differences in the rate of release of amino acids measured in t
his latter system were related both to the type of protein and the origin o
f the enzymes. When using purified mammal enzymes, release of lysine or phe
nylalanine from casein and soybean was high, but low from fishmeal, Isoleuc
ine and valine present in fishmeal were preferentially hydrolyzed by commer
cial enzymes, but glycine and proline by fish enzymes. (C) 2001 Elsevier Sc
ience Inc. All rights reserved.