Monoclonal antibodies to yeast catalase T

Hybridoma cell lines secreting antibodies directed against $\text{Saccharomyces cerevisiae}$ catalase T were constructed by fusing spleen cells of mice immunized with catalase T with P3×63Ag8 mouse myeloma cells. Culture supernatants were assayed for specific antibodies by incubation with ³⁵S-labelled yeast extracts, adsorption of the immune complexes to Protein A — carrying $\text{Staphylococus aureus}$ cells and analysis of the adsorbed yeast proteins by sodium dodecylsulfate gel electrophoresis. Two hybrid clones were isolated mediating adsorption of a protein with electrophoretic mobility of catalase T; one of them, showing considerably higher activity, was characterized further. Anti-bodies produced by this clone belong to the IgG class of immuniglobulins; they can be used for immunoadsorption, but not for direct immunoprecipitation and recognize authentic catalase T as well as catalase T apoprotein.