Radiation-induced Binding of Methanol, Ethanol and 1-butanol to Haemoglobin

Summary

Aqueous solutions of haemoglobin were irradiated under N₂ and under N₂O in the presence of methanol, ethanol and 1-butanol, which were partly ₁₄C-labelled. The amount of bound alcohol was measured after gel filtration on Sephadex G-100 and with sodium dodecyl sulphate on Sepharose 6B-CL. All alcohols became covalently linked to haemoglobin. After radiolysis under N₂ the G values for the three different alcohols were very similar, but under N₂O the yield of cross-linking of haemoglobin with 1-butanol is twice that of methanol or ethanol. The high degree of modification by butanol results in extensive dissociation to dimers. Possible mechanisms yielding covalent cross-links between alcohols and haemoglobin are discussed. The high G value for cross-linking with butanol suggests that butanol radicals can add very efficiently to double bonds.

• radiolysis
• haemoglobin
• alcohol radicals
• gel filtration
• radiation-induced cross-linking