Analysis of denaturation of bovine IgG by heat and high pressure using an optical biosensor

The therapeutic potential of bovine colostrum is generally attributed to its high content of immunoglobulin G (IgG), the physiological activity of which is vulnerable to potentially denaturing conditions during processing. The influence of both thermal and high-pressure treatments on native IgG was evaluated using an optical biosensor immunoassay technique that exploited the simultaneous detection of bovine IgG by both anti-bovine IgG antibody and protein G. Whereas anti-bovine IgG revealed integrity of globally distributed native conformational epitopes, protein G specifically revealed structural stability of the Fc domain. The results confirmed comparable regional stabilities to heat and hydrostatic pressure when isolated IgG was studied, whereas a modest domain differentiation was apparent in colostrum, which may be attributed to the protective effects of unidentified colostral components.