title: Comparative evaluation of manganese peroxidase- and Mn(III)-initiated peroxidation of C18 unsaturated fatty acids by different methods.
abstract: The peroxidation of C18 unsaturated fatty acids by fungal manganese peroxidase (MnP)/Mn(II) and by chelated Mn(III) was studied with application of three different methods: by monitoring oxygen consumption, by measuring conjugated dienes and by thiobarbituric acid-reactive substances (TBARS) formation. All tested polyunsaturated fatty acids (PUFAs) were oxidized by MnP in the presence of Mn(II) ions but the rate of their oxidation was not directly related to degree of their unsaturation. As it has been shown by monitoring oxygen consumption and conjugated dienes formation the linoleic acid was the most easily oxidizable fatty acid for MnP/Mn(II) and chelated Mn(III). However, when the lipid peroxidation (LPO) activity was monitored by TBARS formation the linolenic acid gave the highest results. High accumulation of TBARS was also recorded during peroxidation of linoleic acid initiated by MnP/Mn(II). Action of Mn(III)-tartrate on the PUFAs mimics action of MnP in the presence of Mn(II) indicating that Mn(III) ions are involved in LPO initiation. Although in our experiments Mn(III) tartrate gave faster than MnP/Mn(II) initial oxidation of the unsaturated fatty acids with consumption of O(2) and formation of conjugated dienes the process was not productive and did not support further development of LPO. The higher effectiveness of MnP/Mn(II)-initiated LPO system depends on the turnover of manganese provided by MnP. It is proposed that the oxygen consumption assay is the best express method for evaluation of MnP- and Mn(III)-initiated peroxidation of C18 unsaturated fatty acids.
authors: Institute for Microbial and Biochemical Sciences, USDA Forest Products Laboratory, One Gifford Pinchot Dr., Madison, WI 53726, USA. ankapich@mail.ru
authors: Alexander N
authors: AN
authors: Kapich
authors: Tatyana V
authors: TV
authors: Korneichik
authors: Kenneth E
authors: KE
authors: Hammel
authors: Annele
authors: A
authors: Hatakka
mesh_terms: D001487:Basidiomycota / Q000201:enzymology; D001673:Biodegradation, Environmental; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D015227:Lipid Peroxidation; D008345:Manganese / Q000737:chemistry* / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D010544:Peroxidases / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000378:metabolism
chemical_list: D005231:Fatty Acids, Unsaturated; D017392:Thiobarbituric Acid Reactive Substances; D017962:alpha-Linolenic Acid; D008345:Manganese; D010544:Peroxidases; C051129:manganese peroxidase