Document Detail


Toward understanding the mechanism of chromophore-assisted laser inactivation--evidence for the primary photochemical steps.
MedLine Citation:
PMID:  15623352     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Chromophore-assisted laser inactivation (CALI) is a light-mediated technique used to selectively inactivate proteins of interest to elucidate their biological function. CALI has potential applications to a wide array of biological questions, and its efficiency allows for high-throughput application. A solid understanding of its underlying photochemical mechanism is still missing. In this study, we address the CALI mechanism using a simplified model system consisting of the enzyme beta-galactosidase as target protein and the common dye fluorescein. We demonstrate that protein photoinactivation is independent from dye photobleaching and provide evidence that the first singlet state of the chromophore is the relevant transient state for the initiation of CALI. Furthermore, the inactivation process was shown to be dependent on oxygen and likely to be based on photooxidation of the target protein via singlet oxygen. The simple model system used in this study may be further applied to identify and optimize other CALI chromophores.
Authors:
Elke Horstkotte; Torsten Schröder; Jens Niewöhner; Erwin Thiel; Daniel G Jay; Stefan W Henning
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Photochemistry and photobiology     Volume:  81     ISSN:  0031-8655     ISO Abbreviation:  Photochem. Photobiol.     Publication Date:    2005 Mar-Apr
Date Detail:
Created Date:  2005-06-02     Completed Date:  2005-09-19     Revised Date:  2005-11-17    
Medline Journal Info:
Nlm Unique ID:  0376425     Medline TA:  Photochem Photobiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  358-66     Citation Subset:  IM    
Affiliation:
Xerion Pharmaceuticals AG, Munich, Germany.
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MeSH Terms
Descriptor/Qualifier:
Absorption
Coloring Agents / chemistry
Fluoresceins / chemistry,  radiation effects
Lasers*
Light
Models, Chemical
Oxygen / chemistry
Photochemistry
Singlet Oxygen / radiation effects
Time Factors
beta-Galactosidase / antagonists & inhibitors*,  chemistry,  radiation effects
Chemical
Reg. No./Substance:
0/Coloring Agents; 0/Fluoresceins; 17778-80-2/Singlet Oxygen; 7782-44-7/Oxygen; EC 3.2.1.23/beta-Galactosidase

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


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