title: Hofmeister effects in biology: effect of choline addition on the salt-induced super activity of horseradish peroxidase and its implication for salt resistance of plants.
abstract: The effect of choline addition on the salt-induced super activity of horseradish peroxidase (HRP) is investigated. HRP is presented in the literature as an efficient H(2)O(2) scavenger, and choline is the precursor of glycine betaine, a strong osmoprotectant molecule. Both the regulations of H(2)O(2) and of osmoprotectant concentrations are implicated in plants in order to counteract salt-induced cell damage. For the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), sulfate anions were found to play a crucial role in the increase of HRP activity. This induced super activity can be strongly reduced by adding choline chloride. The phenomena provide an example of physicochemical Hofmeister effects playing a central regulatory role in an important biological system.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Cagliari-CSGI, Cittadella Monserrato, S.S. 554 Bivio Sestu, 09042 Monserrato-Cagliari, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Pinna
authors.forename: P
authors.initials: P
authors.lastname: Bauduin
authors.forename: D
authors.initials: D
authors.lastname: Touraud
authors.forename: M
authors.initials: M
authors.lastname: Monduzzi
authors.forename: B W
authors.initials: BW
authors.lastname: Ninham
authors.forename: W
authors.initials: W
authors.lastname: Kunz
mesh_terms: D002794:Choline / Q000737:chemistry* / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D002794:Choline