title: Lactoperoxidase as a potential drug target.
abstract: BACKGROUND
  Lactoperoxidase (LPO) belongs to the immunologically relevant mammalian heme peroxidases. The enzyme contributes in external secretions to the humoral immune defense against pathogens by oxidation of thiocyanate (SCN(-)) and iodide (I(-)). The generation of oxidized thiocyanate and/or iodine species is also important in numerous biotechnological applications of LPO.
  
  
  METHODS
  In this review, we give an overview about the present knowledge of LPO concerning enzymatic structure, catalytic cycles and (pseudo-)halogenated species generated by the enzyme. Redox properties of LPO as well as kinetic aspects regarding the different enzymatic cycles are discussed in order to gain insights into the disturbance of the (pseudo-)halogenating enzyme activity under pathological conditions. Important structural features of LPO and crystallographic studies on the interaction and reaction of organic substrates with the enzyme are also summarized. A broad discussion is devoted to the binding and oxidation of substrates that either inhibit or promote LPO activity.
  
  
  CONCLUSIONS
  On the basis of these data, different strategies to further optimize LPO functions in humoral defense of mucous surfaces and biotechnological applications are discussed. In particular, hydrophobic organic substrates with a 3,4-dihydroxyphenyl partial structure considerably enhance the (pseudo-)halogenating activity of LPO. Their application provides, thus, a new strategy to enhance the anti-microbial activity of this enzyme.
authors.affiliation: a Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18 , 04107 Leipzig , Germany.|b Translational Centre for Regenerative Medicine (TRM) Leipzig , University of Leipzig , Leipzig , Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Flemmig
authors.affiliation: a Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18 , 04107 Leipzig , Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Gau
authors.affiliation: a Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18 , 04107 Leipzig , Germany.|b Translational Centre for Regenerative Medicine (TRM) Leipzig , University of Leipzig , Leipzig , Germany.
authors.forename: Denise
authors.initials: D
authors.lastname: Schlorke
authors.affiliation: a Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18 , 04107 Leipzig , Germany.|b Translational Centre for Regenerative Medicine (TRM) Leipzig , University of Leipzig , Leipzig , Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Arnhold
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods; D015195:Drug Design; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology; D007454:Iodides / Q000378:metabolism; D007784:Lactoperoxidase / Q000378:metabolism*; D058990:Molecular Targeted Therapy; D010084:Oxidation-Reduction; D013861:Thiocyanates / Q000378:metabolism
chemical_list: D007454:Iodides; D013861:Thiocyanates; D007784:Lactoperoxidase; C031760:thiocyanate
keywords: (pseudo-)halogenating activity; 3,4-dihydroxylated phenylic compounds; heme peroxidases; hypothiocyanite; inflammation; innate immunity; lactoperoxidase; mucous surfaces; myeloperoxidase; oxidized iodine species