[Activation of prekallikrein from human blood serum by different activators].

It was shown that the activated Hageman factor and its active fragment convert a greater amount of prekallikrein into kallikrein than is observed under the effects of trypsin and kallikrein. The latter two enzymes convert from 30 to 60% of the Hageman factor-activated prekallikrein and its active fragment. A possible existence of two prekallikrein forms is discussed. A mechanism of interaction between individual components of the kininogenase system and their activators is discussed.