Characterization of recombinant antibodies for cancer therapy by infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy was used to study the structure of the recombinant antibodies 1E10, anti-CD20 and hR3, which are used as anti-cancer therapeutic drugs. We tested their sensitivity against different conditions and treatments such as pH, temperature, freeze-thaw cycles and drying, which are relevant for the practical usefulness of the drugs. All antibodies were stable against moderate temperature increases (up to 50 degrees C) and pH changes (range 5-9). 1E10 was sensitive to extreme pH values (pH 3 and 12), whereas hR3 was most sensitive to temperature (at and above 60 degrees C). We did not observe any significant changes upon freeze-thaw and drying treatments. The secondary structure content of all three antibodies was estimated to be similar to that of IgG with similar to 64% beta-sheet, 0% alpha-helix and similar to 36% other structure. (C) 2012 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.