Abstract
In order to clarify a motile specificnty of lymphocytes, a contactile protein was extracted from human tonsilar lymphocytes. The purified protein exhibited superprecipitation at low ionic strength in the prerence of Mg++and Ca++, Mg++acivated ATPase activity (EC 3.6. 13.), ATP sensitive viscosity fall and the typical“arrowhead structure” characteristic of myosin B of skeletal muscles electronmicrorcopically. These findings were similar to those of the contractile protein obtained from neutrophils which have reported previously by us except a few points. Judging from the attitudes to Mg++ and Ca++, the protein is a Ca++ sensitive contractile protein, so-called a natural actomyosin, and a smooth murcle type.
The protein was localized in the whole cytoplasma, contrary to that the contractile protein of neutrophils was located only just out of the granular layer, and its quantity was more than neutrophils. An arrangement of the protein was obviously different from that in neutrophils. Studying the change of the contractile protein on the course of cell culture by using FlTC-heavy meromyosin, the fluorescence was also observed in PHA-induced immature lymphocytes that had no motile activity. On the basis of these results, a role of the contractile protein in lymphocytes was discussed.
