Radiation induced structural and functional modification of haemoglobin.

An abnormality in the primary structure of dog haemoglobin was observed 1-20 days after their whole body irradiation with 190 keV X-rays (4.0 Gy). It consisted in a substitution of tryptophane residue in position 15 of the beta-chain for serine. The percentage of abnormal beta-chains in different time intervals after irradiation was determined. The structural changes have functional impact: an increasing haemoglobin affinity to oxygen. This could be explained on the basis of changes in the tertiary structure of haemoglobin, which may result from the substitution Trp 15----Ser15 in the beta-chain which may influence the haeme ability to bind oxygen.