[Electron transfer in hemoproteins. III. Physico-chemical characteristics of autoxidation of sperm whale oxymyoglobin].

The influence of pH, temperature and ionic strength on the autoxidation of sperm whale oxy-Mb is described and the data obtained are discussed. The process depends on the ionization of two groups with pKeff approximately or equal to 6. They are not accessible histidines of Mb. There are two parallel processes of autoxidation and each of them have a different temperature dependence. Two regions of ionic strength of opposite influence on the rats of autoxidation both at "low" (10 degrees C) and "high" (30 degrees C) temperatures were found.