Further studies on an eleventh case of heavy (Hgamma1) chain disease--physico-chemical studies.

An abnormal protein with similar antigenic properties to Fc fragments of IgG, was found in the serum and urine of an eleventh case of heavy (Hgamma1) chain disease (Yok). This protein was purified with ammonium sulfate precipitation and by column chromatography of DEAE cellulose, CM cellulose and Sephadex G-200. The purity of the protein obtained was 98.5%. It was crystallized easily, forming thin hexagonal plates of various sizes. The chemical compositions and physical properties of the protein including viscosity, partial specific volume, diffusion constant, sedimentation constant, frictional ratio, extinction coefficient and iso-ionic point are reported.