title: Magnetization studies of the active and fluoride-inhibited derivatives of the reduced catalase of Lactobacillus plantarum: toward a general picture of the anion-inhibited and active forms of the reduced dimanganese catalases.
abstract: The magnetic properties of the reduced catalase from Lactobacillus plantarum have been studied for the active enzyme and its fluoride complex through variable field/variable temperature magnetization measurements. The magnetic exchange interaction deduced from these experiments [fluoride complex: - J=1.3(1) cm(-1); active enzyme: - J=5.6(5) cm(-1); H=-2 J S(1) S(2)] are similar to those presently obtained in a re-analysis of the data for the corresponding forms of the Thermus thermophilus enzyme (previously published in 1997, Angew Chem Int Ed Engl 36:1626-1628): phosphate complex: - J=2.1(2) cm(-1); active enzyme - J=5.0(3) cm(-1). These results concur to a unified picture for the two enzymes, consistent with the presence of a hydroxide bridge in the reduced active catalases and its replacement by an aqua bridge in the anion-inhibited enzymes as the main mediators of the magnetic exchange.
authors.affiliation: DBMS/Laboratoire de Physicochimie des Métaux en Biologie, Département de Biologie Moléculaire et Structurale (FRE CEA-CNRS-UJF), CEA-Grenoble, 38054 Grenoble Cedex 9, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Le Pape
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Perret
authors.forename: Isabelle
authors.initials: I
authors.lastname: Michaud-Soret
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Latour
mesh_terms: D000838:Anions; D002374:Catalase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D005459:Fluorides / Q000494:pharmacology*; D007778:Lactobacillus / Q000201:enzymology*; D008280:Magnetics; D010084:Oxidation-Reduction
chemical_list: D000838:Anions; D002374:Catalase; D005459:Fluorides