Your browser doesn't support javascript.
loading
pH-induced structural changes of tyrosinase from Agaricus bisporus using fluorescence and in silico methods.
Ionita, Elena; Stanciuc, Nicoleta; Aprodu, Iuliana; Râpeanu, Gabriela; Bahrim, Gabriela.
Afiliação
  • Ionita E; Faculty of Food Science and Engineering, University 'Dunarea de Jos' of Galati, Domneasca Street 111, 800201, Galati, Romania.
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.
Assuntos
Palavras-chave

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Doenças das Plantas / Agaricus / Proteínas Fúngicas / Monofenol Mono-Oxigenase / Frutas Idioma: En Ano de publicação: 2014 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Doenças das Plantas / Agaricus / Proteínas Fúngicas / Monofenol Mono-Oxigenase / Frutas Idioma: En Ano de publicação: 2014 Tipo de documento: Article