溶血性連鎖球菌溶血毒素の研究

(Weld溶血毒素生成因子に就いて)

抄録

It has long been well known that a highly potent hemotoxin is obtainable by shaking for a short period of time the bacterial bodies of hemolytic streptococcus suspended in blood serum. The hemotoxin thus obtainable was named “Weld's hemotoxin.” However, no details as to the production mechanisms and production factors have ever been elucidated as yet. Meanwhile, the fact that even more highly potent hemotoxin is obtainable when solution of nucleic acid is employed in stead of blood serum has been found by Hosoya, Egami and Hayashi. Anticipating that the reality of the production factors in the blood serum might be consisting of the minute amount of nucleic acid contained in the serum, the authors fractionated blood serum following Schneider's method, and the hemotoxin production capacity of each fraction was investigated. As the results of this investigation, it was learnt that the nucleic acid fraction possesses almost no capacity of toxin production, but that most part of the capacity is transferred to its protein fraction. However, since it was also suspected that nucleic acid might have lost its capacity owing to such drastic chemical procedures as Schneider's fractionation method, the authors treated nucleic acid before investigating its production capacity, and found that its capacity is reduced not remarkably. When Hammersten's casein, which is considered to be a relatively pure protein, was employed in place of blood serum, the hemotoxin was also obtainable. In this case again, it was found that most part of the production capacity is transferred to its protein fraction. In view of the above facts, it was elucidated that the production factors of the Weld's hemotoxin do not exist in the minute amount of nucleic acid contained in the blood serum, but exist inn the serum protein.
In an attempt to learn as to which fraction of the serum protein contains the factor, the serum protein was fractionated by Cohn's low temperature ethanol fractionation, and the hemotoxin production capacity of each fraction was investigated. This experiment revealed that, although the capacity is divided to each of the fractions to certain extent, the largest portion is transferred to globulin fraction, and only a small portion is transferred to the albumin fraction. Furthermore, it was made clear that the albumin fraction is not the production factors, but that the globulin fraction contains the principal portion, because, when the albumin fraction was further purified and isolated, it was found to be containing almost no hemotoxin production capacity.