Pulse Radiolysis Study of Catalytic Properties of Human Manganese Superoxide Dismutase: A Review

Abstract

The depletion of superoxide catalyzed by human manganese superoxide dismutase (MnSOD) was observed spectrophotometrically by measuring the absorbance of superoxide at 250-280 nm following pulse radiolysis and it showed a biphasic pattern. Tryptophan 161 is a highly conserved residue that forms a hydrophobic side of the active site cavity of manganese superoxide dismutase (MnSOD), with its indole ring adjacent to and about 5 Å from the manganese. Trp 161 promotes the dissociation of product peroxide, perhaps in part through its effect on the orientation of Tyr 34.