THE SIZE, SHAPE AND HYDRATION OF LOBSTER HEMOCYANIN

Abstract

The sedimentation coefficient of lobster hemocyanin corrected to water at 20[degree] and extrapolated to zero concentration was found to be 24.5 x 10-13 cgs units. The intrinsic viscosity was 4.85 ml/ml. From variation of the sedimentation rate of hemocyanin in sucrose solutions of different densities and from partial specific volume, the hydration of hemocyanin was calculated to be 0.15 ml of water/g of dry protein. Specific refractive increment was determined to be 0.00193 ml/ 10-2g. From the above parameters and others taken from literature, lobster hemocyanin molecules were calculated to have a molecular weight of 825,000, corresponding to oblate ellipsoids of revolution with hydrated diameter of 32.2 m[mu] and hydrated thickness of 7.8 m[mu]. Electron micrographs are consistent with the assumption that molecules are plate-like ellipsoids of revolution 33 m[mu]. in diameter and 7.5 m[mu] in thickness in the dried state.