Abstract: | In the extracellular space of the tissue of the sponge Geodia cydonium, circular proteid particles are found which carry as subunits the aggregation factor and a series of glycosyltransferases. Using the technique of velocity sucrose gradient centrifugation, the sedimentation coefficient (S020,w) of the particle-monosomes was determined to be 90. By means of the Svedberg equation a molecular weight of 1.3 . 10(8) daltons could be estimated. The monosomes aggregate in the presence of Ca2+ to higher complexes via disomes, trisomes, and pentasomes. The complexes can be redissociated by dodecyl sulfate but not by EDTA. During the Ca2+-mediated self-aggregation, the particles lose their biological activity with respect to their aggregation promoting function. |