[Immunoglobulin G peculiar to cancer]

The physicochemical methods showed that in the blood serum of patients with different forms of malignant growth, including myeloma, there exists protein which cannot be detected by the same methods in the serum of healthy people. Using ion-exchange chromatography protein was isolated and characterized by some physicochemical and biological parameters. The protein is established to belong to immunoglobulins G but it does not represent the whole function in reactions with antisera, it reacts only against gamma-heavy chains. The sedimentation constant and molecular weight testify to this fact as well. Peculiarities of amino acidic composition, conformation and structure are typical of the protein. The characteristic immunoglobulin G has a unique property of activating glycolysis and inhibiting oxygen uptake as well as of removing the Paster reaction. The physicochemical and biological peculiarities features are peculiar not only to the whole molecule but also to Fab fragment of characteristic immunoglobulin G. By using immunosorbents it was possible to show that a part of characteristic protein is in the composition of the immune complexes. The results of the model experiments with rats on studying biosynthesis of proteins peculiar to the malignant growth give reasons to suggest that proteins peculiar to these processes are synthetized anew. A correlation is found between the processes of protein synthesis and changes in mRNA transcription. On the basis of the data presented a conclusion is drawn on community of the malignant growth at the level of biosynthesis and ejection into the blood bed the peculiar proteins--malignancy markers.