Aggregation of sponge cells. Isolation and characterization of an inhibitor of aggregation receptor from the cell surface.

From the cell membranes of the sponge Geodia cydonium a component was isolated and purified which inhibits the aggregation factor isolated from the same source; the component was termed anti-aggregation receptor. This molecule was characterized as a glycoprotein (54% neutral carbohydrate) and its molecular weight is in the range of 180,000 One biological site of the anti-aggregation receptor was determined to be D-galactose. Indirect evidence presented seems to indicate that this molecule is present in an active form in aggregation-deficient cells and absent in aggregation-susceptible cells.