title: Conjugation in Tetrahymena pyriformis. The effect of polylysine, concanavalin A, and bivalent metals on the conjugation process.
abstract: The polycation polylysine, at different degrees of polymerization, was found to cause a marked inhibition of the conjugation process. Inhibition of conjugation by polylysine was highly dependent on the molecular weight of the polymer. When polylysine of a mol wt of 1,250 (degree of polymerization=6) was used, a concentration of 1.6 X 10(-5) M was required for a complete inhibition of conjugation, while only 2 X 10(-7) M of polylysine of a mol wt of 71,000 (degree of polymerization=340) was needed for the same effect. Polyaspartic acid prevented the inhibition of conjugation by polylysein. Chelators of bivalent metals such as O-phenanthroline (10(-3) M), EDTA (10(-3) M), and EGTA (5 X 10(-3) M) strongly inhibit the conjugation process in Tetrahymena pyriformis. The inhibition was partially prevented when bivalent metals such as Zn++, Fe++, and Ca++ were added together with the chelators. The lectin concanavalin A (25 mug/ml) completely prevented the conjugation process, while other lectins, such as phytohemagglutinin (500 mug/ml), soybean agglutinin (75 mug/ml) and wheat germ agglutinin (250 mug/ml) had no effect. Inhibition of conjugation by concanavalin A is completely reversible by 40 mM of alpha-methyl-D-mannoside.
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D003208:Concanavalin A / Q000494:pharmacology*; D003227:Conjugation, Genetic / Q000187:drug effects*; D003911:Dextrans / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D005944:Glucosamine / Q000494:pharmacology; D008766:Methylmannosides / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010618:Phenanthrolines / Q000494:pharmacology; D011107:Polylysine / Q000494:pharmacology*; D013769:Tetrahymena pyriformis / Q000187:drug effects / Q000502:physiology*
chemical_list: D003911:Dextrans; D008766:Methylmannosides; D010455:Peptides; D010618:Phenanthrolines; D003208:Concanavalin A; D011107:Polylysine; D001224:Aspartic Acid; D004533:Egtazic Acid; D004492:Edetic Acid; D005944:Glucosamine