[New data on carbonic acid fixation in animals and man]

Recently a new enzymic carboxylation reaction has been discovered at the final-step of prothrombin and other proteins synthesis. The presence of the unique amino acid, gamma-carboxyglutaminic acid, is established and its structure is determined. The role of the acid is shown in Ca2+ fixation in the known proteins, playing an important role in the blood coagulation processes, and in some new proteins participating in the tissue calcification. Data are systematized on the necessity of vitamin K in the new reaction of the carbonic acid fixation under conditions of its in vitro simulation.