Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/196323
Type: Artigo de periódico
Title: Tendency For Oxidation Of Annelid Hemoglobin At Alkaline Ph And Dissociated States Probed By Redox Titration.
Author: Bispo, Jose Ailton Conceicao
Landini, Gustavo Fraga
Santos, Jose Luis Rocha
Norberto, Douglas Ricardo
Bonafe, Carlos Francisco Sampaio
Abstract: The redox titration of extracellular hemoglobin of Glossoscolex paulistus (Annelidea) was investigated in different pH conditions and after dissociation induced by pressure. Oxidation increased with increasing pH, as shown by the reduced amount of ferricyanide necessary for the oxidation of hemoglobin. This behavior was the opposite of that of vertebrate hemoglobins. The potential of half oxidation (E1/2) changed from -65.3 to +146.8 mV when the pH increased from 4.50 to 8.75. The functional properties indicated a reduction in the log P50 from 1.28 to 0.28 in this pH range. The dissociation at alkaline pH or induced by high pressure, confirmed by HPLC gel filtration, suggested that disassembly of the hemoglobin could be involved in the increased potential for oxidation. These results suggest that the high stability and prolonged lifetime common to invertebrate hemoglobins is related to their low tendency to oxidize at acidic pH, in contrast to vertebrate hemoglobins.
Subject: Animals
Annelida
Chromatography, High Pressure Liquid
Conductometry
Electrochemistry
Hemoglobins
Hydrogen-ion Concentration
Microscopy, Electron, Transmission
Oxidation-reduction
Pressure
Solubility
Rights: fechado
Identifier DOI: 10.1016/j.cbpc.2005.06.002
Address: http://www.ncbi.nlm.nih.gov/pubmed/15982915
Date Issue: 2005
Appears in Collections:Unicamp - Artigos e Outros Documentos

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