抄録
1. Sedimentation constants, diffusion coefficients and partial specific volumes of native ferro-, ferri-cytochrome c, and of ferri-cytochrome c modified by trichloroacetic acid were measured. Sedimentation constants at 20° in water (S20, w) are 1.87, 1.91 and 2.50 Svedberg units for native ferro-, ferri- and modified ferri-cytochrome c, respectively. Diffusion coef-ficients at 20° in water (D20, w) are 12.9×10-7, 13.2×10-7 and 8.5×10-7cm.2/ sec. for native ferro-, ferri- and modified ferri-cytochrome c, respectively. The partial specific volumes of these different kinds of cytochrome c's are 0.70.
2. From these values, the molecular weight of the native cytochrome c is calculated to be 12, 000 and that of modified ferri-cytochrome c to be 24, 000. This indicates that the molecules of modified cytochrome c exist as dimers of molecules similar to those of native cytochrome c.
The author would like to express his thanks to Prof. K. Okunuki and Dr. T. Horio for their valuable guidance, and is grateful to Prof. T. Isemura and Prof. K. Fukai of this university for helpful advice on the physicochemical measurements.
