Biochemical and spectroscopic characterization of catechol oxidase from sweet potatoes (Ipomoea batatas) containing a type-3 dicopper center.
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 NH2-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 A for the native met form and 3.8 A for the oxy form.
Eicken
C
C
Anorganisch-Chemisches Institut der Universität Münster, Germany.
Zippel
F
F
Büldt-Karentzopoulos
K
K
Krebs
B
B
D000595:Amino Acid Sequence; D004156:Catechol Oxidase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D003300:Copper / Q000032:analysis*; D004577:Electron Probe Microanalysis; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D018517:Plant Roots; D011487:Protein Conformation; D016415:Sequence Alignment; D019657:Solanaceae / Q000201:enzymology*; D011198:Solanum tuberosum; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013053:Spectrophotometry; D013379:Substrate Specificity
D010446:Peptide Fragments; D003300:Copper; D004156:Catechol Oxidase