[Antigenic composition of prealbumin fraction of bull brain water-soluble proteins].

The antigenic composition was studied in the fraction of prealbumins obtained by preparative electrophoresis in the agar hel of proteins salted out from the aqueous extract of bull cerebral hemispheres with amminiom sulphate within saturation limits of 60-100% (fraction 0.6-1). The chickens antisera immunized with the fraction of bull brain prealbumins were used in the experiment. One organospecific and species-nonspecific antigen called the antigen D is found by the method of immunoelectrophoresis in the components of the prealbumin fraction by means of the antisera obtained. This antigen is detected in water-soluble proteins of the bull great cerebral hemispheres and optic nerve. The antigen immunologically identical to that of the bull is contained in the aqueous extract of the rabbit and rat brain and is not found in the chicken brain.