Document Detail


Inhibition of histidine ammonia lyase by 8-methoxypsoralen and psoralen-oxidized photoproducts.
MedLine Citation:
PMID:  20880231     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of 8-methoxypsoralen-UVA therapy on the catalysis of histidine to trans-urocanic acid by histidine ammonia lyase (HAL, EC 4.3.1.3) was examined using an enzymatic assay from Sigma-Aldrich where the growth of the trans-urocanic acid peak at 277 nm was monitored. A Rayonet Photochemical Mini Reactor (Model RMR-600) equipped with eight, 3500 Å light sources and a custom UVA filter (Model S-BAL3 2.9 mm), from the Solar Light Company, were used to expose various reaction mixtures to broadband UVA light and UVA/UVB light. A UV-Vis spectrophotometer (Model Shimadzu UV 2540) with a temperature-controlled cell holder (Model TCC240) was used to monitor the growth of the trans-urocanic peak. Results of dark-binding experiments of 8-methoxypsoralen in denatured ethanol indicate no inhibition of enzyme activity due to ethanol but noncompetitive inhibition due to 8-methoxypsoralen. The effects of preirradiated 8-methoxypsoralen, with both broadband UVA and UVA/UVB, indicate that inhibition was due to psoralen-oxidized photoproducts. Inhibition of HAL was found when exposed to broadband UVA/UVB and to a lesser extent when exposed to broadband UVA.
Authors:
John T Reilly; Kyle A Troester; Trista T Tyner; Dominick A Vitale; Tiffiany R Risher
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2010-09-29
Journal Detail:
Title:  Photochemistry and photobiology     Volume:  86     ISSN:  1751-1097     ISO Abbreviation:  Photochem. Photobiol.     Publication Date:    2010 Nov-Dec
Date Detail:
Created Date:  2010-11-24     Completed Date:  2011-03-21     Revised Date:  2011-04-11    
Medline Journal Info:
Nlm Unique ID:  0376425     Medline TA:  Photochem Photobiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1272-7     Citation Subset:  IM    
Copyright Information:
© 2010 The Authors. Journal Compilation. The American Society of Photobiology.
Affiliation:
Department of Chemistry and Physics, Coastal Carolina University, Conway, SC, USA. jreilly@coastal.edu
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MeSH Terms
Descriptor/Qualifier:
Histidine Ammonia-Lyase / antagonists & inhibitors*
Humans
Immunosuppression
Methoxsalen / pharmacology*
Oxidation-Reduction
PUVA Therapy
Photochemical Processes
Photosensitizing Agents / pharmacology
Skin Diseases / drug therapy,  enzymology,  immunology
Urocanic Acid / metabolism
Chemical
Reg. No./Substance:
0/Photosensitizing Agents; 104-98-3/Urocanic Acid; 298-81-7/Methoxsalen; EC 4.3.1.3/Histidine Ammonia-Lyase
Comments/Corrections
Erratum In:
Photochem Photobiol. 2011 Mar-Apr;87(2):487

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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