Conformational changes in bovine lactoferrin induced by slow or fast temperature increases.
Biol Chem
; 389(8): 1137-42, 2008 Aug.
Article
em En
| MEDLINE
| ID: mdl-18979637
ABSTRACT
Lactoferrin (LF) is an iron-binding protein present in several secreted substances, such as milk, and has broad antimicrobial and physiological properties. Because high temperatures may affect protein stability and its functional properties, we investigated the effect of heat on bovine LF structure and stability. The effects of temperatures used during the pasteurization process on LF and its relationship to protein functionality were studied. Conformational changes were monitored using spectroscopic techniques, such as circular dichroism (CD) and fluorescence spectroscopy. The CD data at 70 degrees C showed that LF's secondary structure is drastically and irreversibly affected when the temperature is gradually increased. The same effect is observed when the temperature is gradually raised from 25 degrees C to 105 degrees C and changes are monitored by tryptophan fluorescence emission. We also verified the effects of simulating the pasteurization process; LF remained well structured during the entire process and this result was not time-dependent. Owing to preservation of the secondary structure with changes in the tertiary structure, we thus believe that pasteurization might cause LF to change into an intermediate partially folded state. A better understanding of heat stability is important for the use of LF as a bioactive component in food.
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Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Lactoferrina
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biol Chem
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Brasil