Study of haem structure of photo-deligated haemoglobin by picosecond resonance Raman spectra.

It is well known that the oxygen affinity of haemoglobin depends on the number of combined oxygen molecules. This cooperative effect is considered to arise from a reversible protein transition between two forms which differ in tertiary and quaternary structure. However, the various steps of the structural changes concerning the protein and the haem have not been identified. Using time-resolved spectroscopy coupled to flash photolysis, we have attempted to elucidate the influence of protein on the relaxation processes of haem in haemoglobin. We now report our first results obtained in a picosecond time-resolved resonance Raman study of haemoglobin.