Immunologically Symmetrical Proteolysis

If 0.1 cc. horse serum is added to 1.9 cc. canine leucocytic extract and the mixture is incubated over night, titration of the resulting lytic products by means of ice-chest ripened rabbit precipitin gives precipitin graphs suggesting a 400% to 800% test-tube multiplication of horse proteins, without appreciable horse protein denaturization. The simplest explanation of this apparent increase is to assume that under the influence of leucocytic proteolysin each horse protein molecule is hydrolysed into from 4 to 8 daughter protein molecules, each daughter molecule being of approximate horse protein specificity.