Bullous pemphigoid antigen: isolation from normal human skin.

A protein moiety from epidermal PBS-soluble products was isolated by gel filtration (Bio-Gel A-1.5m) and ion exchange chromatography (DEAE-cellulose). This protein (A-1-Epid) was not retarded by DEAE-cellulose in Tris-HCl buffer, 15mM, pH 8.1. By IEP against an antiserum to epidermal antigens, it showed a single cathodal arc. On disc electrophoresis, at low pH (4.3) a single band was apparent. On SDS gels this protein demonstrated two bands, one with a molecular weight of 20,000, and the second with a molecular weight of 9,200. This purified antigen was able to block the staining of the basement membrane zone produced by bullous pemphigoid antibodies on monkey esophagus and normal human skin with the use of indirect immunofluorescence. This study also demonstrates that bullous pemphigoid antigen (A-1-Epid) and a second epidermal protein (A-2-Epid) are present in the PBS-soluble products of human esophageal mucosa, saliva, and urine. These antigens appear to be unrelated with the blood group substances or secretor status of the donors.