pH-induced structural changes of tyrosinase from Agaricus bisporus using fluorescence and in silico methods.
J Sci Food Agric
; 94(11): 2338-44, 2014 Aug.
Article
em En
| MEDLINE
| ID: mdl-24425348
ABSTRACT
BACKGROUND:
Tyrosinases are involved in enzymatic browning reactions in damaged fruits during post-harvest handling and processing. The overall structure of tyrosinase from Agaricus bisporus mushrooms at different pH values was monitored using fluorescence spectroscopy and molecular dynamics simulations.RESULTS:
When the pH value was increased from 6.0 to 9.0, the protein passed through several structural intermediates, including the tetramer, trimer and dimer stages. Changes in the secondary and tertiary structure of tyrosinase at neutral pH were outlined after running molecular dynamics simulations. A detailed check at the single-molecule level by means of molecular modeling tools suggested that the most important contribution to the fluorescence intensity is given by the H subunits with seven Trp and nine Tyr residues exposed to the solvent, whereas the lectin-like folded L subunits have only six Trp and three Tyr residues, of which only Trp(15) , Trp(59) and Trp(93) are partially exposed to the solvent.CONCLUSIONS:
The results indicated that the enzyme was sensitive to pH. The experimental results revealed the unfolding of the native tetrameric enzyme in acidic pH range, causing exposure of the hydrophobic residues.Palavras-chave
Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
/
Agaricus
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Proteínas Fúngicas
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Monofenol Mono-Oxigenase
/
Frutas
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article