[Optical and ESR-spectroscopic study of electronic adducts of oxymyoglobin and oxyhemoglobin].

It has been shown that low temperatures (77 degrees K) irradiation of frozen water-glycerol solutions of oxymyoglobin and oxyhemoglobin induces kinetically stabilized nonequilibrium electronic adducts (MbO2-, HbO2-) at the expense of binding of thermolyzed electrons formed during matrix radiolysis to oxygenated hem iron. The absorption spectra of HbO2-and MbO2- have a wide band with the maximum at 545 nm and Soret's band at 421 nm. At 77 K MbO2- gives the ESR spectrum with g beta 1 = 2.203 and g beta 2 = 2.103. Unlike the latter HbO2- ESR spectrum consists of two signals g beta 1 = 2.234, g beta 2 = 2.135 and g alpha 1 = 2.195, g alpha 2 = 2.103. Two signals in HbO2- spectra are shown to be conditioned by electronic adducts of oxygenated alpha- and beta-subunits. The observed effect points to non-equivalency of O2 in alpha- and beta-subunits of oxyhemoglobin. Binding of inositolhexaphopshate to oxyhemoglobin induces changes in the electron structure of HbO2-active centres.