Purification and properties of ascorbate free-radical reductase from potato tubers.
Ascrobate free-radical reductase (EC 1.6.5.4) from potato tubers was purified to apparent homogencity by a method which included ammonium-sulfate precipitation, gel filtration and chromatography on diethylaminoethyl cellulose and hydroxylapatite. Gel filtration and gel electrophoresis showed that the purified enzyme was monomeric with a molecular weight of about 42 000. Enzyme activity was heat lable and severely inhibited by thiol reagents. The Km values for enzyme substrates were estimated.
Istituto di Botanica, Università di Bari, I-70126, Bari, Italy.
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Borraccino
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Dipierro
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Arrigoni