Cross-reactions between protamines of different species: the role of arginine clusters

Human and monkey sera containing autoantibodies to protamines reveal often strong cross-reactions with protamines of other species including salmon protamine. These cross-reactions can be readily detected both in the immunofluorescence test and th micro-complement fixation test. These sera react to a much lesser extent with poly-L-arginine. The results indicate that the cross-reactions of these protamines are not primarily due to clusters of arginine.