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    A Purple Acid Phosphatase from Sweet Potato Contains an Antiferromagnetically Coupled Binuclear Fe-Mn Center


    Schenk, Gerhard and Boutchards, Clare and Carrington, Lyle E. and Noble, Christopher J. and Moubaraki, Boujemaa and Murray, Keith S. and de Jersey, John and Hanson, Graeme R. and Hamilton, Susan E. (2001) A Purple Acid Phosphatase from Sweet Potato Contains an Antiferromagnetically Coupled Binuclear Fe-Mn Center. Biochemistry, 276 (22). pp. 19084-19088. ISSN 0006-2960

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    Abstract

    A purple acid phosphatase from sweet potato is the first reported example of a protein containing an enzymatically active binuclear Fe-Mn center. Multifield saturation magnetization data over a temperature range of 2 to 200 K indicates that this center is strongly antiferromagnetically coupled. Metal ion analysis shows an excess of iron over manganese. Low temperature EPR spectra reveal only resonances characteristic of high spin Fe(III) centers (Fe(III)-apo and Fe(III)-Zn(II)) and adventitious Cu(II) centers. There were no resonances from either Mn(II) or binuclear Fe-Mn centers. Together with a comparison of spectral properties and sequence homologies between known purple acid phosphatases, the enzymatic and spectroscopic data strongly indicate the presence of catalytic Fe(III)-Mn(II) centers in the active site of the sweet potato enzyme. Because of the strong antiferromagnetism it is likely that the metal ions in the sweet potato enzyme are linked via a m-oxo bridge, in contrast to other known purple acid phosphatases in which a m-hydroxo bridge is present. Differences in metal ion composition and bridging may affect substrate specificities leading to the biological function of different purple acid phosphatases.

    Item Type: Article
    Keywords: Purple Acid Phosphatase; Sweet Potato; Antiferromagnetically Coupled Binuclear Fe-Mn Center;
    Academic Unit: Faculty of Science and Engineering > Chemistry
    Item ID: 3706
    Depositing User: Gary Schenk
    Date Deposited: 30 May 2012 09:16
    Journal or Publication Title: Biochemistry
    Publisher: American Chemical Society
    Refereed: Yes
    URI:
      Use Licence: This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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