THE EFFECTS OF PASTEURIZATION ON ALBUMIN - AN EPR BINDING ASSAY FOR POLYMERIC ALBUMIN

The ability of a nitroxyl fatty acid (NFA) to bind specifically to alb umin is abolished when, in the absence of stabilizers, a 4% solution o f this protein is heated above a critical temperature of 60 degrees C. This treatment leads to the formation of ''albumin polymers'' as clas sically evidenced by GPC. Since the bound fraction is evidenced in EPR spectroscopy by a large anisotropic component, the presence of this a nisotropy can. be used in the assessment of the quality of the pharmac eutical preparations of albumin, which are usually pasteurized in orde r to inactivate viruses. Moreover, in sharp contrast with the behavior of albumin dispersions, lyophilised albumin subjected to heat treatme nt at 70 degrees C for 24 h left the protein untouched regarding its N FA binding and GPC profile.