[Optical spectroscopy of methemoglobin from the Lampetra fluviatilis river lamprey and its complexes reduced at 77K]

The absorption spectra from met-haemoglobin from lamprey Lampetra fluviatilis and its complexes with F-, CN-, N3- and imidazole were studied in non-equilibrium states arising in low-temperature (77K) reduction of water-glycerol of oxidized forms of protein with thermolyzed electrons. The Soret band was shown to be not split in low-temperature absorption spectra of reduced met-haemoglobin and its complexes unlike that of the equilibrium deoxyhaemoglobin. It was concluded that met-haemoglobin has a higher symmetry of the active centre as compared to deoxyhaemoglobin.