Abstract
Concanavalin A at a concentration of 1.0 mg/ml completely inhibited the conjugation of haploid cells of Physarum polycephalum. This inhibitory effect was counteracted by α-methyl-D-mannoside. α-Mannosidase also inhibited conjugation. Neither wheat germ agglutinin nor lentil lectin had any apparent inhibitory effects. When Physarum cells were cultured in the presence of tunicamycin at a concentration of 1 μ/ml, a similar inhibitory effect on conjugation was observed. The plasma membrane from the amoebae partially inhibited conjugation. On the basis of these results, the mannosyl glycoprotein(s) located on the cell surface is considered to function in conju-gation process.
Inhibitory compounds could be extracted from the cell surface with the detergent, Triton CF-54, and could be separated by concanavalin A-Sepharose column chromatography.
