IMMUNOLOGICAL ACTIVITIES OF IGG ANTIBODY ON PRE-COATED FC RECEPTOR SURFACES

The immunological activities of an IgG antibody bound on Fc receptors, such as protein A and protein G, pre-coated on a glassy carbon electr ode surface have been studied. In order to discriminate the effects of molecular orientation and the conformation retention of the antibody on a protein sublayer, the activities of the antibody chemically coupl ed to both bare and bovine serum albumin (BSA)-pre-coated electrode su rfaces were also determined. A non-competitive sandwich electrochemica l enzyme immunoassay was applied to determine the relative surface act ivities. It was shown that the general antigen binding ability of the antibody on the protein A surface was the highest among the four immob ilisation techniques used, whereas the activity on the BSA-modified su rface was the lowest. Although the antibody coupled on the protein G s urface also offers a certain degree of orientation, its general activi ty showed no large increase compared to that of antibody bound to the bare electrode surface, since the concentration of the antibody on its surface was lower than that of the bare surface.