Studies on the Fibrinolysin Produced by the Hemolytic Streptococcus

[摘要] 1. 1. Fibrinolysin is highly specific for human fibrinogen; it does not act, in the quantities tested, on dog, sheep, and rabbit fibrinogens.2. 2. Human serum globulins are not attacked by fibrinolysin although fibrinogen, which is a globulin or is present in the globulin fraction of blood plasma, is acted upon.3. 3. The action of fibrinolysin on fibrin formed by animal fibrinogen and human thrombin is peculiar in that both animal fibrinogen and human thrombin are unaffected by fibrinolysin when either is present alone, but when the two are combined and mixed with fibrinolysin the clot becomes susceptible to liquefaction.4. 4. Human thrombin is capable of inactivating fibrinolysin; sheep thrombin does not possess this ability, even if it is permitted to act on the fibrinolysin for 20 hours.5. 5. Liquefaction of fibrin-clots formed by human fibrinogen and either human or sheep thrombin results in the disappearance of the thrombin from the liquefied material. It was suggested that the formation of fibrin alters the state of both the fibrinogen and the thrombin. This is in keeping with the observations that when a fibrin-clot forms from fibrinogen and thrombin a large proportion of the thrombin disappears just as the clot solidifies. It has been assumed that the disappearance of the thrombin is due to its being taken up in the clot. However, from the present study it appears that the thrombin actually becomes altered or inactivated. The inactivation, however, does not invalidate the theory that thrombin is an enzyme.

[学科分类] 生物科学（综合）