AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Collins, P. J.
Right arrow Articles by Dobson, A. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Collins, P. J.
Right arrow Articles by Dobson, A. D.
Agricola
Right arrow Articles by Collins, P. J.
Right arrow Articles by Dobson, A. D.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol., 07 1997, 2543-2548, Vol 63, No. 7
Copyright © 1997, American Society for Microbiology

Stabilization of lignin peroxidases in white rot fungi by tryptophan

PJ Collins, JA Field, P Teunissen and AD Dobson
Microbiology Department, University College, Cork, Ireland.

Supplementation of various cultures of white rot fungi with tryptophan was found to have a large stimulatory effect on lignin peroxidase activity levels. This enhancement was greater than that observed in the presence of the lignin peroxidase recycling agent veratryl alcohol. Using reverse transcription-PCR, we found that tryptophan does not act to induce lignin peroxidase expression at the level of gene transcription. Instead, the activity enhancement observed is likely to result from the protective effect of tryptophan against H2O2 inactivation. In experiments using a partially purified lignin peroxidase preparation, tryptophan and its derivative indole were determined to function in the same way as veratryl alcohol in converting compound II, an oxidized form of lignin peroxidase, to ferric enzyme, thereby completing the catalytic cycle. Furthermore, tryptophan was found to be a better substrate for lignin peroxidase than veratryl alcohol. Inclusion of either tryptophan or indole enhanced the oxidation of the azo dyes methyl orange and Eriochrome blue black. Stimulation of azo dye oxidations by veratryl alcohol has previously been shown to be due to its enzyme recycling function. Our data allow us to propose that tryptophan stabilizes lignin peroxidase by acting as a reductant for the enzyme.


This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1997 by the American Society for Microbiology. All rights reserved.