Nanosecond laser photolysis of aqueous carbon monoxy- and oxyhaemoglobin.

The spectra have been measured of the transient species and the final level of absorption observed in nanosecond laser photolysis of aqueous carbon monoxy- and oxyhaemoglobin. These show that the transient absorption change can be interpreted as being due to an ultrafast ligand recombination following the photolysis. The spectra do not support the earlier interpretation (Alpert, B., Banerjee, R. and Lindqvist, L. (1974) Proc. Natl. Acad. Sci. U.S. 71, 558--562) that this was due to a tertiary structural change of the protein.