Abstract
In a previous note 1 we reported that under the influence of canine leucocytic extract horse proteins undergo an initial pseudo-proliferation, presumably due to immunologically symmetrical proteolysis. A similar apparent multiplication of horse proteins takes place on 14-day incubation with an excess (20:1) of normal canine serum. In both cases the apparent multiplication is followed by a marked flattening and distortion of the precipitin graph 2 which we interpret as an index of horse protein denaturization. 3
In contrast with this parenteral type of proteolysis, gastro-intestinal proteolysis has thus far given in our hands no suggestion of pseudo-proliferation and subsequent partial denaturization. If 5% horse serum is added to 0.1% commercial trypsin in Ringer's solution, for example, or to 0.1% commercial pepsin in acidulated (n/100) Ringer's solution and the mixture is incubated at 37.5° C. for several hours, precipitin graphs show from the first a rapid and consistent decrease in horse-protein titer, without flattenings or distortions of the precipitin graph. We interpret this as meaning that in gastro-intestinal proteolysis none of the lytic products retain their original horse protein specificity.
This study represents selected data from 20 titrations of test-tube lytic products. Each titration was accompanied by parallel tests of from 2 to 4 non-lytic controls.
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