Analysis of Soluble Antigens in Guinea-Pig Epidermis.

Five tissue specific antigens in guinea-pig epidermis were characterized by heat treatment, enzyme digestion, DEAE-cellulose chromatography, (NH₄)₂SO₄ precipitation, ethanol precipitation and gel filtration. These antigens appeared to be proteins although one was fairly resistant to proteinases. Two antigens (Sp2a and Sp2b) were heat-stable and precipitated at high (NH₄)₂SO₄ concentration (3.0 M—saturation): Sp2b was also precipitated at very high ethanol concentration (50-90 per cent). On electrophoresis, Sp2a was shown to have three distinct molecules, while Sp2b showed two. The molecular weight of one component of Sp2a was 71,000 and that of one component of Sp2b was 13,500, as determined by gel filtration. A third antigen behaved electrophoretically and chromatographically like γ-globulin, but was separated from it by (NH₄)₂SO₄ precipitation. The other two antigens did not show any characteristic features and behaved like many other non-specific tissue antigens. [ABSTRACT FROM AUTHOR]