Figure 2.

Model of proposed heme-heme and heme-NADPH linkage in human catalase. (Upper panel) Model illustrating functional dimmer in 1.5A structure of human catalase.¹⁴ (Lower panel) Position of migrating potential tyrosinate radical in adjacent protein domains. We speculate that the migration of this radical facilitates the formation of an electronic charge relay linkage associating two heme moieties in each functional dimer.^{13,22,26,33,36}