Physico-chemical properties of the fertilizins of the sea urchin Arbacia punctulata and the sand dollar Echinarachnius parma.

摘要: Measurements have been made of the sedimentation rates, diffusion, viscosity and electrophoretic mobilities fertilizins sea urchin Arbacia punctulata sand dollar Echinarachnius parma. From data for a molecular weight 280,000 is calculated, value 300,000 considered more probable. The axial ratio estimated to be 28 1, calculated an unhydrated prolate ellipsoid 20 1 if 0.4 gram water assumed bound per fertilizin. fertilizin sedimented slowly than that Arbacia. measurements show these highly acidic as had found in other species. This also permitted calculations valence 14.25 effective negatively charged groups molecule at pH 7 11.25 4.85. amount absorbed single spermatozoon binds approximately 100,000 molecules, therefore possesses least many receptor sites. relation this certain features fertilization briefly discussed.