Phenothiazines are slowly oxidizable substrates of horseradish peroxidase


1. Yakutsk State Agricultural Academy
Type: Experimental/clinical study
DOI: 10.18097/PBMC20115705544      UDK: 577.152.1      PubMed Id: 22629605
Year: 2011 vol: 57  issue:5  pages: 544-553
Abstract: Reactions of peroxidase oxidation of triftazine and thioproperazine have been investigated in the presence of horseradish peroxidase using steady state kinetic methods. It has been shown that phenothiazines are slowly oxidizable substrates for horseradish peroxidase. kcat and Km values have been determined in the range of pH from 4.5 to 7.5. The study of co-oxidation of phenothiazines and o-dianisidine (ODN) revealed that in the presence of aminazine and ODN in the reaction medium both substances follow sequential oxidation. ODN oxidation was not observed until full conversion of aminazine. At pH 4.5-5.5 thioproperazine bound to the enzyme-substrate complex and caused a nticompetitive inhibition of peroxidase. At pH>5.5 sequential substrate oxidation with preferential thioproperazine conversion occurred. In the range of pH from 4.5 to 7.5 triftazine did not influence ODN oxidation.
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Reference: Rogozhina T.V., Rogozhin V.V., Phenothiazines are slowly oxidizable substrates of horseradish peroxidase, Biomeditsinskaya khimiya, 2011, vol: 57(5), 544-553.
This paper is also available as the English translation:10.1134/S1990750811040093