Antifreeze proteins differentially affect model membranes during freezing.
Biochim Biophys Acta
; 1511(2): 255-63, 2001 Apr 02.
Article
en En
| MEDLINE
| ID: mdl-11286968
Over the past decade antifreeze proteins from polar fish have been shown either to stabilize or disrupt membrane structure during low temperature and freezing stress. However, there has been no systematic study on how membrane composition affects the interaction of antifreeze proteins with membranes under stress conditions. Therefore, it is not possible at present to predict which antifreeze proteins will protect, and which will damage a particular membrane during chilling or freezing. Here, we analyze the effects of freezing on spinach thylakoid membranes and on model membranes of varying lipid composition in the presence of antifreeze protein type I (AFP I) and specific fractions of antifreeze glycoproteins (AFGP). We find that the addition of galactolipids to phospholipid model membranes changes the effect each protein has on the membrane during freezing. However, the greatest differences observed in this study are between the different types of antifreeze proteins. We find that AFP type I and the largest molecular weight fractions of AFGP induce concentration dependent leakage from, and are fusogenic to the liposomes. This is the first report that an antifreeze protein induces membrane fusion. In contrast, the smallest fraction of AFGP offers a limited degree of protection during freezing and does not induce membrane fusion at concentrations up to 10 mg/ml.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tilacoides
/
Proteínas Anticongelantes
/
Congelación
/
Membrana Dobles de Lípidos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos