Abstract
1) A substance reacting with SDS-treated small spherical forms of HBsAg was found frequently in HBeAg positive sera of persistent antigenemia. (2) This substance reacted with anti-HBs antibody as well. 3) The density of this substance was estimated as 1.21 by equillibrium buoyant centrifugation. 4) The sedimentation rate of the substance fell between those of Dane particles and small spherical forms of HBsAg, and was identical to that of tubular forms. 5) The reactivity of the substance disappeared by digestion with pronase.
These data imply the existence of a specific protein on the tubular forms in the sera positive for HBeAg, reacting with the inner structure of the HBsAg.
