Ramasarma, T. and Vaigundan, D. (2019) Pathways of electron transfer and proton translocation in the action of superoxide dismutase dimer. Biochemical and Biophysical Research Communications, 514 (3). pp. 772-776. ISSN 0006-291X

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Abstract

Superoxide dismutase, known to gain large rate enhancement on dimerization, forms a homodimer stabilized by hydrogen bonding between a number of internal water molecules and a few amino acid residues at the interface. Within each subunit the β-sheets provide a sequence of delocalized π-electron units of peptide bonds alternating with hydrogen bonds referred as π-H pathway. These pathways in the two subunits in the dimer are interlinked through a chain of four water molecules bridged by hydrogen bonds at the interface. Connecting the two Cu-centers this π-H pathway can enable rapid electron transfer from one superoxide molecule to the other, crucial for the catalytic reaction and the high rate in the dimer. A proton relay of hydrogen-bonded water molecules in the dimer translocates protons to form the product, hydrogen peroxide.

Item Type:	Article
Uncontrolled Keywords:	Beta sheets; Copper zinc enzyme; Dimer; Proton relay; Rate enhancement; Superoxide dismutase; π-H pathway
Subjects:	Molecular Biology
Depositing User:	Users 2 not found.
Date Deposited:	16 May 2019 12:28
Last Modified:	30 May 2019 11:08
URI:	http://cdfd.sciencecentral.in/id/eprint/902

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