ELECTRON SPIN RESONANCE STUDIES OF CATALASE COMPLEXES

Beef liver catalase, as well as some catalase complexes, were examined at a temperature of 77 °K by applying the method of electron spin resonance. It was revealed that-just as with the complexes of other hemoproteins catalse complexes may be divided into high-spin complexes, low-spin complexes and mixed complexes, consisting of both forms, depending on their respective electron spin resonance spectra. At a neutral pH, beef liver catalase itself yields an electron spin resonance spectrum with axial symmetry and absorptions at g = 6 and g - 2; thus, catalase is a high spin complex. The following catalase complexes have electron spin resonance spectra with these absorptions; catalase fluoride and catalase formate. The low-spin complexes manifested electron spin resonance spectra of a lower symmetry with 3 g factors at about 2. Only catalase cyanide is a pure low-spin complex. The mixed complexes of both complex forms indicate an absorption at g = 6 and a broad absorption with 3 g factors at about 2. The following catalase complexes have electron spin resonance spectra with these absorptions: catalase acetate, catalase azide, H2S-catalase, catalse cyanate and catalase thiocyanate. © 1968.