| Literature DB >> 16971216 |
Cléberson F Fernandes1, Vadjah C P Moraes, Ilka M Vasconcelos, Joaquim A G Silveira, José T A Oliveira.
Abstract
Two isoperoxidases were detected in cowpea (Vigna unguiculata) leaves. Treatment of the primary leaves with 10mM salicylic acid increased the total peroxidase activity contributed by the anionic isoform. To isolate both the anionic and cationic peroxidases the leaf crude extract was loaded on a Superose 12 HR 10/30 column followed by chromatography on Mono-Q HR 5/5. Both enzymes were stable in a pH range from 5 to 7. The optimum-temperatures for the cationic and anionic peroxidase isoforms were, respectively, 20-30 degrees C and 30 degrees C. The dependence of guaiacol oxidation rate varying its concentration at constant H(2)O(2) concentration showed, for both enzymes, Michaelis-Menten-type kinetic. Apparent K(m)(s) were 0.8 and 4.8 microM for the cationic and anionic isoperoxidases, respectively.Entities:
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Year: 2005 PMID： 16971216 DOI： 10.1016/j.jplph.2005.06.021
Source DB: PubMed Journal: J Plant Physiol ISSN： 0176-1617 Impact factor: 3.549