Proton linkage for CO binding and redox properties of bovine lactoperoxidase
| Autor: | Stefano Marini, Giampiero De Sanctis, Alessandro Arcovito, Roberto Santucci, Pia Ferrari Rosa, Andrea Bellelli, Chiara Ciaccio, Federica Sinibaldi, Elena Maria Ghibaudi, Massimo Coletta |
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| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Hemeprotein
Inorganic chemistry Kinetics Biophysics lactoperoxidase Plasma protein binding Heme carbon monoxide laser photolysis Redox Catalysis chemistry.chemical_compound Reaction rate constant Animals Binding site Settore BIO/10 Settore BIO/10 - BIOCHIMICA Binding Sites CO photolysis Lactoperoxidase Proteins Milk Protons Enzyme Activation Hydrogen-Ion Concentration Protein Binding Oxidation-Reduction Cattle Carbon Monoxide chemistry |
| Zdroj: | Biophysical journal 86 (2004): 448–454. info:cnr-pdr/source/autori:Ciaccio C, De Sanctis G, Marini S, Sinibaldi F, Santucci R, Arcovito A, Bellelli A, Ghibaudi E, Ferrari Rosa P, Coletta M./titolo:Proton linkage for CO binding and redox properties of bovine lactoperoxidase./doi:/rivista:Biophysical journal (Print)/anno:2004/pagina_da:448/pagina_a:454/intervallo_pagine:448–454/volume:86 Scopus-Elsevier |
| Popis: | The pH-dependence of redox properties and of CO binding to bovine lactoperoxidase has been investigated over the range between 2 and 11. The pH-dependence of redox potentials shows a biphasic behavior, suggesting the existence of (at least) two redox-linked groups, which change their pKa values upon reduction. These values are in close agreement with those observed to play a relevant role in the modulation of CO binding to ferrous bovine lactoperoxidase. They have been tentatively attributed to Arg-372 and His-226, which are located on the distal side of the heme pocket of lactoperoxidase. A complete and unequivocal description of the proton-linked behavior of bovine lactoperoxidase requires, however, three residues, which are redox linked and relevant for the modulation of CO binding. The rate constant for CO binding to bovine lactoperoxidase is slower than what is reported for most hemoproteins, suggesting that these two residues, Arg-372 and His-226, are representing a severe barrier for the access of exogenous ligands to the heme. This aspect has been further investigated by fast kinetics following laser photolysis, trying to obtain information on the ligand binding pathway and on the energy barriers. |
| Databáze: | OpenAIRE |
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