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Biochemical and spectroscopic characterization of catechol oxidase from sweet potatoes ( Ipomoea batatas ) containing a type‐3 dicopper center 1
Author(s) -
Eicken Christoph,
Zippel Frank,
Büldt-Karentzopoulos Klaudia,
Krebs Bernt
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01113-2
Subject(s) - ipomoea , catechol , chemistry , molecular mass , isoelectric focusing , electron paramagnetic resonance , monomer , isoelectric point , extended x ray absorption fine structure , isozyme , catechol oxidase , nuclear chemistry , enzyme , crystallography , stereochemistry , polyphenol oxidase , biochemistry , absorption spectroscopy , biology , nuclear magnetic resonance , organic chemistry , botany , peroxidase , physics , quantum mechanics , polymer
Two catechol oxidases have been isolated from sweet potatoes ( Ipomoea batatas ) and purified to homogeneity. The two isozymes have been characterized by EXAFS, EPR‐, UV/Vis‐spectroscopy, isoelectric focusing, and MALDI‐MS and have been shown to contain a dinuclear copper center. Both are monomers with a molecular mass of 39 kDa and 40 kDa, respectively. Substrate specificity and NH 2 ‐terminal sequences have been determined. EXAFS data for the 39 kDa enzyme reveal a coordination number of four for each Cu in the resting form and suggest a Cu(II)‐Cu(II) distance of 2.9 Å for the native met form and 3.8 Å for the oxy form.