Partial purification of pemphigus-related epidermal antigens.

Epidermal antigens partially purified by either isoelectric focusing (the pH 5.2 peak) or concanavalin A (Con A) affinity chromatography react with Con A in tube precipitation reactions. Bands of identity between crude skin antigens, the Con A affinity antigens eluted with alpha-methyl glucoside and the pH 5.2 peak are formed in Ouchterlony gel with rabbit antisera (Rab) to the pH 5.2 antigen. Absorption of Rab or pemphigus antibodies (Pab) with A+ erythrocytes does not affect complement fixation reactions of Rab with the skin antigen nor abolish the ability of Pab to interact with the intercellular cement. The pH 5.2 epidermal antigens react weakly with Pab in tube precipitation reactions and only weakly, if at all, to inhibit Pab reactions in the region of the intercellular cement. High concentrations of Con A inhibit the Pab, peroxidase-anti-IgG tissue reaction whereas the converse inhibition does not occur. Simultaneous use of both Pab and Con A-perodixase reactions at Con A concentrations which do not inhibit Pab, causes enhanced tissue peroxidase reactions in the region of the intercellular cement. These preliminary data indicate that the Pab and Con A-reacting sites are localized on different molecules or antigenic determinants in the intercellular cement. They exclude the possibility that A-blood substances are involved in either site.