| 摘要 |
The new structure of the interaction of IgG with an antigen and a complement is proposed. According to this structure, the signal passes into the Fc fragment by a switch of the hinge region with its bend ''in two'' and the interaction of the changed hydrophobic patches of the Fab fragments with the Fc fragment. The changed conformation of the Fc fragment, especially in the pFc' region, became similar in shape to a scorpion's tail which could presumably interact by its hydrophobic patches in the outside face of the CH3 domain with the complement component C1 to activate the complement. The analysis of data from old literature gives strong evidence for this ''scorpion'' structure. It is proposed that the small protein (m.w. SIMILAR 2000) associated with IgG (Dudich, E.I. and Dudich, I. Dokl. Acad. Sci. USSR 260,1259, 1981) serves as the IgG protector against a strong interaction with the complement. The dissociation of this small protein, after a large distorsion during the precipitation reaction with an antigen, allows for a strong fixation of the globular heads of the C1q subcomponent. The proposed structure explains: the role of an affinity in the aggregation and in the complement activation; and consequently, the mechanisms of a great number of associated diseases. This ''scorpion'' structure explains the interaction between B and T-lymphocytes which is exemplified by both types of experimental results, that is, by direct interaction as well as by interaction with soluble substances. The examples with extremely important practical consequences are proposed. |
