Specific S-methylglutathione incorporation into a nematocyst-rich fraction of hydra.
1. Specific S-[C]methylglutathione incorporation from Hydra japonica into a nematocyst-rich subcellular fraction was observed. 2. This specific incorporation is not rapid reversible binding, as shown by the lack of saturation of the reaction with time. 3. Saturating kinetics of specific incorporation rate with S-[14C]methylglutathione concentration suggests the existence of intermediate reversible complex between a macromolecular and S-[14C]methylglutathione. 4. Activity of specific incorporation could be solubilized by Triton X-100 treatment of the nematocyst fraction, showing that the incorporation is not due to transport processes. 5. The incorporation was markedly diminished by the addition of cold trichloroacetic acid or urea, or by heat-treatment after the incorporation, showing that the complex is not stabilized by chemical bonding. 6. No chemical changes of free S-[14C]methylglutathione were detected in the reaction mixture, showing that the macromolecule interacting with S-[14C]methylglutathione is not a catalyzing enzyme. 7. These results suggest that this is a new type of glutathione incorporation and could be explained by a type of receptor protein which accumulates glutathione molecules.
D000818:Animals; D001693:Biological Transport, Active; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D006829:Hydra / Q000378:metabolism*; D007700:Kinetics; D011956:Receptors, Cell Surface / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
D011956:Receptors, Cell Surface; D005978:Glutathione; C017514:S-methyl glutathione