Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/194237
Type: Artigo de periódico
Title: Liposome Effect On The Cytochrome C-catalyzed Peroxidation Of Carbonyl Substrates To Triplet Species.
Author: Nantes, I L
Faljoni-Alario, A
Vercesi, A E
Santos, K E
Bechara, E J
Abstract: Cytochrome c exhibits peroxidase activity on diphenylacetaldehyde (DPAA) and 3-methylacetoacetone (MAA), which is greatly affected by the presence and nature of charged liposome or micelle interfaces interacting with the enzyme. The ferricytochrome c reaction with DPAA is accelerated when the enzyme is attached to negatively charged interfaces. Whatever the medium, bulk solution or negatively charged dicetylphosphate (DCP), phosphatidylcholine/phosphatidylethanolamine/cardiolipin (PC/PE/CL) liposomes, this chemiluminescent reaction is accompanied by reduction of cytochrome c to its ferrous form. In turn, MAA is oxidized by cytochrome c exclusively when bound to DCP liposomes. Contrary to DPAA oxidation, the MAA reaction is followed by bleaching of cytochrome c, reflecting damage to the hemeprotein chromophore. The cytochrome-c-catalyzed oxidation of either DPAA or MAA leads to concomitant disappearance of the enzyme charge transfer absorption band at 695 nm. This suggests that the peroxidase activity of cytochrome c involves substrate-induced loss of the methionine ligand at the iron sixth coordination position, which is favored by interaction of cytochrome c with negatively charged interfaces. Accordingly, a decrease and blue shift of the charge transfer band could be observed in cytochrome-c-containing negatively charged DCP, PC/PE/CL liposomes or lysophosphatidylethanolamine micelles in the presence of DPAA or MAA.
Subject: Acetaldehyde
Acetone
Animals
Cardiolipins
Cytochrome C Group
Kinetics
Liposomes
Luminescent Measurements
Oxidation-reduction
Oxygen Consumption
Peroxidase
Phosphatidylcholines
Phosphatidylethanolamines
Rats
Rats, Wistar
Spectrophotometry
Rights: fechado
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/9741591
Date Issue: 1998
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_9741591.pdf146.55 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.